WO2025033942A1 - Method for evaluating and improving safety of robot - Google Patents

Abstract

A method for evaluating safety of a robot according to an aspect of the present invention includes the steps of: obtaining shape information, mass information, and thermal information of a test robot; obtaining motion profile information of the test robot; calculating a physical amount applied on a collision object by considering injury-inducing hazard shape information, the mass information, the thermal information, and the motion profile information of the test robot; and evaluating the safety of the test robot by considering the size of the calculated physical amount.

Description

Safety assessment of robots and methods for improving safety

The present invention relates to a safety evaluation and safety improvement method of a robot.

Recently, with the realization of high-performance test robots, various efforts are being made to maximize operating convenience and ensure safety by preventing collisions with workers during operation of test robots.

Since these test robots can be installed in the same workspace as humans, accidents due to collisions frequently occur during operation. Therefore, what is essential for test robots is motion precision and motion safety. Among these, in the case of motion precision, motor precision control technology has developed to reach a certain level, but in the case of motion safety, the technical perfection is very low compared to motion precision.

In particular, with the term safety emerging as a key topic in test robot systems recently, various studies are being conducted to improve the safety of test robots.

However, most of the safety evaluation methods for currently developed robots involve installing separate devices on actual test robots to measure collision pressure, collision force, and movement speed, which increases the evaluation cost.

In addition, during safety evaluation, the test robot repeatedly stopped and started more than necessary, which reduced work efficiency and put a strain on the test robot.

To solve these problems, a method was implemented to measure the collision force applied to the body according to the movement of the test robot. However, since the collision force was measured by applying a constant pressure regardless of the shape of the collision site of the test robot, there was a problem in that the accuracy of the safety evaluation was low.

The task of the present invention is to provide a safety evaluation method and a safety improvement method of a robot, which improve the accuracy of safety evaluation by calculating collision pressure and collision force applied to a worker according to the moving speed and moving path of each part considering the shape of a test robot, and determining whether the calculated values correspond to the International Organization for Standardization (ISO) standards.

According to one feature of the present invention for achieving the above-mentioned task, a safety evaluation method of a robot comprises the steps of: acquiring shape information, mass information, and thermal information of a test robot; acquiring motion profile information of the test robot; calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, thermal information, and motion profile information of the test robot; and evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity.

In the above-described configuration, the test robot has at least one joint, thermal information of the test robot includes at least one of temperature and thermal conductivity, motion profile information of the test robot includes at least one of position, velocity and acceleration of the joint at a single or multiple points in time, the calculated physical quantity includes at least one of force, pressure, energy, contact time and thermal energy, and the step of evaluating safety evaluates safety by comparing the calculated physical quantity with the size of a preset physical quantity.

Another aspect of the present invention provides a method for improving the safety of a robot, comprising: a step of acquiring shape information, mass information, and thermal information of a test robot; a step of acquiring motion profile information of the test robot; a step of calculating a physical quantity applied to a collision target by considering injury-causing risk shape information, mass information, thermal information, and motion profile information of the test robot; a step of evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity; and a step of modifying the motion profile information or proposing a modified motion profile based on the evaluated safety.

In the above-described configuration, the test robot has at least one joint, thermal information of the test robot includes at least one of temperature and thermal conductivity, motion profile information of the test robot includes at least one of position, velocity and acceleration of the joint at a single or multiple points in time, the calculated physical quantity includes at least one of force, pressure, energy, contact time and thermal energy, and the step of evaluating safety evaluates safety by comparing the calculated physical quantity with the magnitude of a preset physical quantity, and the step of modifying the motion profile information or proposing a modified motion profile is provided to increase safety or productivity.

A safety evaluation method of a robot according to another feature of the present invention comprises the steps of: acquiring shape information and mass information of a test robot; acquiring shape information of the test robot as a single or combined shape of one or more basic units; acquiring motion profile information of the test robot; calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, and motion profile information of the test robot; and evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity.

In the above-described configuration, the test robot has at least one joint, and the shape information of the test robot of a single or combination of one or more basic units is directly input by a user, or is set by replacing the shape information of the test robot that has already been acquired with the shape of the basic unit, and the motion profile information of the test robot includes at least one of the position, velocity, and acceleration of the joint at a single or multiple points in time, and the physical quantity includes at least one of force, pressure, energy, and contact time, and the step of evaluating the safety evaluates the safety by comparing the size of the calculated physical quantity with the size of the preset physical quantity.

According to another feature of the present invention, a method for improving the safety of a robot comprises the steps of: acquiring shape information and mass information of a test robot; acquiring shape information of the test robot as a single or combined shape of one or more basic units; acquiring motion profile information of the test robot; calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, and motion profile information of the test robot; evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity, and modifying the motion profile information or proposing a modified motion profile based on the evaluated safety.

In the above-described configuration, the test robot has at least one joint, and the shape of the test robot of a single or combination of one or more basic units is directly input by a user, or is set by replacing the shape information of the test robot that has already been acquired with the shape of the basic unit, the motion profile information of the test robot includes at least one of the position, velocity, and acceleration of the joint at a single or multiple points in time, and the physical quantity includes at least one of force, pressure, energy, and contact time, and the step of evaluating the safety evaluates the safety by comparing the calculated physical quantity with the size of the preset physical quantity, and the step of modifying the motion profile information or proposing a modified motion profile is provided to increase safety or productivity.

According to another feature of the present invention, a safety evaluation method of a robot comprises the steps of: acquiring mass information of a test robot; acquiring measurement information of the test robot by measuring basic information that can be configured through a sensor; acquiring shape information by replacing the measurement information with shape information of two or more dimensions; acquiring motion profile information of the test robot; calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, and motion profile information of the test robot, and evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity.

In the above-described configuration, the test robot has at least one joint, the measurement information includes two-dimensional or more data at a single or multiple points in time, the motion profile information of the test robot includes at least one of a position, a velocity, and an acceleration of the joint at a single or multiple points in time, the calculated physical quantity includes at least one of a force, a pressure, an energy, and a contact time, and the step of evaluating the safety evaluates the safety by comparing the calculated physical quantity with a size of a preset physical quantity.

According to another feature of the present invention, a method for improving the safety of a robot comprises the steps of: acquiring mass information of a test robot; acquiring measurement information of the test robot by measuring basic information that can be configured through a sensor; acquiring shape information by replacing the measurement information with shape information of two or more dimensions; acquiring motion profile information of the test robot; calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, and motion profile information of the test robot; evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity, and modifying the motion profile information or proposing a modified motion profile based on the evaluated safety.

In the above-described configuration, the test robot has at least one joint, the measurement information includes two-dimensional or more data at a single or multiple points in time, the motion profile information of the test robot includes at least one of a position, a velocity, and an acceleration of the joint at a single or multiple points in time, the calculated physical quantity includes at least one of a force, a pressure, an energy, and a contact time, and the step of evaluating the safety evaluates the safety by comparing the calculated physical quantity with a size of a preset physical quantity, and the step of modifying the motion profile information or proposing a modified motion profile is provided to increase the safety or productivity.

A safety evaluation method of a robot according to another feature of the present invention comprises the steps of: acquiring shape information and mass information of a test robot; acquiring spatial information; acquiring motion profile information of the test robot; calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, motion profile information, and spatial information of the test robot; and evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity.

In the above-described configuration, the test robot has at least one joint, the spatial information includes at least one of a work area of the test robot, a non-workable area of the test robot, and an obstacle area, the motion profile information of the test robot includes at least one of a position, a velocity, and an acceleration of the joint at a single or multiple points in time, the calculated physical quantity includes at least one of a force, a pressure, an energy, and a contact time, and the step of evaluating the safety evaluates the safety by comparing the calculated physical quantity with a size of a preset physical quantity.

A method for improving safety according to another feature of the present invention comprises the steps of: acquiring shape information and mass information of a test robot; acquiring spatial information; acquiring motion profile information of the test robot; calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, motion profile information, and spatial information of the test robot; evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity; and modifying the motion profile information or proposing a modified motion profile based on the evaluated safety.

In the above-described configuration, the test robot has at least one joint, the spatial information includes at least one of a work area of the test robot, an inoperable area of the test robot, and an obstacle area, the motion profile information of the test robot includes at least one of a position, a velocity, and an acceleration of the joint at a single or multiple points in time, the calculated physical quantity includes at least one of a force, a pressure, an energy, and a contact time, the step of evaluating the safety evaluates the safety by comparing the calculated physical quantity with a size of a preset physical quantity, and the step of modifying the motion profile information or proposing a modified motion profile is provided to utilize the spatial information to increase the safety or productivity.

A safety evaluation method of a robot according to another feature of the present invention comprises the steps of: acquiring shape information and mass information of a test robot; acquiring measurement information of a sensor; acquiring motion profile information of the test robot; calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, motion profile information of the test robot, and the measurement information; and evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity.

In the above-described configuration, the test robot has at least one joint, the measurement information includes at least one of position, velocity and acceleration information of a human body or a body part recognized by a sensor, the motion profile information of the test robot includes at least one of position, velocity and acceleration of the joint at a single or multiple points in time, the calculated physical quantity includes at least one of force, pressure, energy and contact time, and the step of evaluating the safety evaluates the safety by comparing the calculated physical quantity with a size of a preset physical quantity.

According to another feature of the present invention, a method for improving the safety of a robot comprises the steps of: acquiring shape information and mass information of a test robot; acquiring measurement information of a sensor; acquiring motion profile information of the test robot; calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, motion profile information of the test robot, and the measurement information; evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity; and modifying the motion profile information or proposing a modified motion profile based on the evaluated safety.

In the above-described configuration, the test robot has at least one joint, the measurement information includes at least one of position, velocity and acceleration information of a human body or a body part recognized by a sensor, the motion profile information of the test robot includes at least one of position, velocity and acceleration of the joint at a single or multiple points in time, the calculated physical quantity includes at least one of force, pressure, energy and contact time, the step of evaluating the safety evaluates the safety by comparing the calculated physical quantity with the magnitude of a preset physical quantity, and the step of modifying the motion profile information or proposing a modified motion profile is provided to increase the safety or productivity.

According to the present invention, safety evaluation and safety improvement under various conditions and environments for a test robot can be expected.

Figure 1 is a flow chart of a method for improving the safety of a robot according to one embodiment of the present invention.

FIG. 2 is a flowchart for explaining a detailed process for setting the movement time and movement path of the test robot in FIG. 1.

Figure 3 is a schematic diagram illustrating a state in which an actual robot and a colliding object collide.

Figure 4 is a drawing showing changes in the surface of a colliding body in Figure 3 that collides with an actual robot.

Figure 5 is a drawing showing the three-dimensional shape of the test robot in Figure 1.

Figure 6 is a drawing showing the size of the contact pressure applied to the impacted body according to the shape of each part of the test robot.

Figure 7 is a drawing showing the values of collision pressure and collision force obtained through a 3D modeling program.

Figure 8 is a diagram showing the control status of a robot that maximizes productivity and safety through speed control.

Figure 9 is a drawing showing a state in which the path is modified by setting the joint angle to maximize safety.

FIG. 10 is a flow chart for explaining a safety evaluation method of a robot according to another embodiment of the present invention, and is a flow chart regarding a robot safety evaluation method including a technology for analyzing thermal hazards due to contact.

Fig. 11 is a drawing for explaining the thermal risk according to contact time in the embodiment shown in Fig. 10.

FIG. 12 is a flowchart for explaining a robot safety evaluation method by the shape of a basic unit according to another embodiment of the present invention.

Figure 13 is a drawing schematically explaining a technology for automatically matching a unit shape to a robot shape in the present invention.

Figure 14 is a flowchart for explaining a safety evaluation method of a robot according to another embodiment of the present invention.

Figure 15 is a diagram for explaining the process of calculating shape information based on the image of a typical test robot in Figure 14.

Figure 16 is a flowchart for explaining a safety evaluation method of a robot according to another embodiment of the present invention.

Figure 17 is a flowchart for explaining a robot safety evaluation method according to another embodiment of the present invention.

Figure 18 is a block diagram showing the sensor-integrated risk judgment/control intelligent device of Figure 17.

Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. However, the idea of the present invention is not limited to these embodiments, and may be proposed differently by addition, change, deletion, etc. of components forming the embodiments, but this is also included in the idea of the present invention.

FIG. 1 is a flowchart for a method for evaluating and improving the safety of a robot according to one embodiment of the present invention, and FIG. 2 is a flowchart for explaining a detailed process for a step of setting the movement time and movement path of a test robot in FIG. 1.

Fig. 3 is a drawing schematically illustrating a state in which an actual robot and a collided object collide, and Fig. 4 is a drawing illustrating surface changes of the collided object colliding with the actual robot in Fig. 3. Fig. 5 is a drawing illustrating a three-dimensional shape of the test robot in Fig. 1.

As illustrated in FIGS. 1 to 5, the method for improving the safety of a robot (S100) includes a step of obtaining a three-dimensional shape of a test robot (S110), a step of setting a moving time and a moving path of the test robot (S120), a step of evaluating the safety of the test robot at regular intervals (S130), a step of calculating a maximum speed of the test robot in which the magnitude of collision pressure and collision force falls within a preset allowable safety standard, and a step of resetting the moving time and the moving path of the test robot (S150).

In the step (S110) of acquiring a three-dimensional shape of the test robot, a three-dimensional image or a three-dimensional model of the test robot (10) including shape information of the actual robot (R) is acquired. Specifically, the test robot (10) may be formed as a three-dimensional image formed by inputting shape information of the robot (R) into a simulation program, or as a three-dimensional model formed through a three-dimensional measurement sensor. That is, the test robot (10) may be a three-dimensional image formed by inputting shape information of the actual robot (R) into a simulation program such as a CAE (Computer Aided Engineering) program, or as a three-dimensional model implemented through a three-dimensional measurement sensor and driven and controlled in the same way as the actual robot (R).

The type of robot (R) being 3D modeled is not limited, but may be a collaborative robot that jointly processes work in a certain work space. Such a collaborative robot may be formed as a manipulator equipped with a mechanical hand at the tip to grasp and transport a specific object or perform a specific task. In addition, the test robot (10) may be formed to have a degree of freedom that allows movement in at least one direction among the X-axis direction, the Y-axis direction, the Z-axis direction, the pitch direction, the yaw direction, and the roll direction. That is, the test robot (10) may be formed as a manipulator having at least one degree of freedom.

Specifically, the test robot (10) may be formed as a manipulator including at least two link parts (12) connected through joints (11) and an end effector (13) connected to one of the link parts (12). Here, the end effector is a part that has a function of directly acting on a work target when the test robot (10) performs a work, and may be, for example, a mechanical hand of the manipulator.

In the step (S120) of setting the movement time and movement path of the test robot, profile information including the movement time information and movement path information of the test robot (10) is input to set the movement time and movement path of the test robot (10). For example, if the test robot (10) is a three-dimensional image, the movement time and movement path of the test robot (10) can be set by inputting profile information including the movement time information and movement path information into the simulation program. If the test robot (10) is a three-dimensional model, the movement time and movement path of the test robot (10) can be set by inputting profile information including the movement time information and movement path information into the control system of the test robot (10). Here, since the method of controlling the operation of the test robot (10) through the simulation program and the control system of the robot is already a known technology, a detailed description thereof will be omitted.

In the step (S130) of evaluating the safety of the robot at regular intervals, the shape, effective mass, moving speed, and direction of the injury-risk area of the test robot (10) are taken into consideration to obtain the collision pressure (P) and collision force (force, F _C ) applied to the impacted body (20) at regular intervals, and the safety of the robot (R) is evaluated by determining whether the magnitude of the collision pressure and collision force obtained at regular intervals is within the magnitude of the preset maximum collision pressure (P _MAX ) and maximum collision force (F _MAX ).

Here, the preset maximum collision pressure (P _MAX ) and maximum collision force (F _MAX ) can be set to sizes according to the International Organization for Standardization (ISO) standards. The International Organization for Standardization (ISO) discloses the maximum allowable pressure and force that each part of the human body can withstand. Therefore, setting the maximum collision pressure (P _MAX ) and maximum collision force (F _MAX ) based on these standards can further improve the safety of the robot (R).

The reason for obtaining the collision pressure (P) and collision force (F _C ) applied to the colliding body (20) by dividing them into a certain time unit is to reduce the amount of data for calculating the collision pressure (P) and collision force (F _C ), thereby improving the calculation speed and preventing a load from being applied. Here, the time determined in a certain unit may vary depending on the shape of the robot (10). That is, the more complex the shape of the robot (10), the shorter the unit time may be.

Specifically, the collision force (F _C ) applied to the collided body (20) can be implemented through the following mathematical expression 1. Here, the collided body (20) can be a human, and the effective mass (M _i ) for the collision site of the test robot is calculated by the kinematic theory, and the effective mass (M _h ) for the collision site of the collided body can be input by the user and determined in advance. The displacement (y _i ) of the collision site of the test robot and the displacement (y _h ) of the collision site of the collided body can be obtained through the CAE system.

M _i : effective mass of the impact site of the test robot

M _h : effective mass of the impactor at the point of impact

F _C : Collision force

y _i : Displacement of the impact site of the test robot

y _h : Displacement of the impact site of the colliding body

And, the collision pressure (P) applied to the impacted body (20) can be implemented through the following mathematical expression 2. Here, the skin elasticity (K) of the impacted body and the skin thickness (h) of the impacted body can be input by the user through the CAE system and stored in advance.

δ: amount of skin deformation of the impactor,

α: Collision angle between the test robot and the impactor,

F _c : collision force, p : collision pressure,

K: skin elasticity of the impacted body, h: skin thickness of the impacted body,

x, y: collision plane coordinate system

The step of setting the movement time and movement path of the test robot (S120) may further include the step of setting an injury-risk area of the test robot (S121), the step of changing the posture of the test robot and calculating the collision pressure and collision force applied to the collided body, respectively (S122), the step of selecting and storing the minimum collision pressure and minimum collision force applied to the collided body (S123), and the step of changing the joint angle and moving the test robot (S124).

In the step (S121) of setting the risk of injury-causing parts of the test robot, the contact pressure applied to the impacted body (20) is calculated according to the shape of each part of the test robot (10), and at least one risk of injury-causing part of the test robot (10) is set using the calculated contact pressure value.

For example, if the test robot (10) is formed in a cylindrical shape, each part of the test robot (10) for setting the risk of injury may be a circumferential surface, an upper surface, a lower surface, an upper edge, and a lower edge. Then, the contact pressure applied to the impacted body (20) is calculated according to the shape of each part. Here, the method for calculating the contact pressure can be calculated through the relationship P=F/A (P: pressure, F: force, A: area).

Through this process, when the contact pressure for each part of the test robot (10) is calculated, the part with the largest value among the contact pressures or the part whose contact pressure exceeds a preset value can be selected as a part at risk of causing injury.

Meanwhile, the risk of injury-causing parts of the test robot (10) may be determined by one or more selections of the user. Specifically, the risk of injury-causing parts of the test robot (10) may be one or more selected from among the link part (12) and the end effector (13). In this way, if the risk of injury-causing parts of the test robot (10) are preset by the user, the step (S121) of setting the risk of injury-causing parts of the test robot may be omitted.

In the step (S122) of changing the posture of the test robot and calculating the collision pressure and collision force applied to the collided body, respectively, the joint angle of the test robot (10) is adjusted to change the posture of the link part (12) and the end effector (13), and the collision pressure (P) and collision force (F _C ) applied to the collided body (20) by the injury-causing risk area according to the change in posture are calculated, respectively.

The reason for calculating the collision pressure (P) and collision force (F _C ) applied to the collided body (20) by changing the posture of the robot (10) in this way is that the distance and contact area with the collided body (20) change depending on the change in posture of the link part (12) and the end effector (13), and as a result, the size of the collision pressure (P) and collision force (F _C ) applied to the collided body (20) also changes.

In the step (S123) of selecting and storing the minimum collision pressure and minimum collision force applied to the colliding body, the smallest values (hereinafter referred to as “minimum collision pressure (P _MIN ) and minimum collision force (F _MIN )”) among the collision pressure (P) and collision force (F _C ) obtained in the previous step (S122) are selected and stored. At this time, the obtained minimum collision pressure (P _MIN ) and minimum collision force (F _MIN ) can be selected and stored at regular intervals.

In the step (S124) of moving the test robot while changing the joint angle, the test robot (10) is moved while changing the joint (11) angle at regular intervals to an angle corresponding to the minimum collision pressure (P _MIN ) and the minimum collision force (F _MIN ).

In this way, by obtaining and storing the size of the minimum collision pressure (P _MIN ) and minimum collision force (F _MIN ) applied to the collided body (20) according to the change in the posture of the test robot (10), and then controlling the posture of the test robot (10) at regular intervals based on this, it becomes possible to implement a posture in which the minimum impact is applied to the collided body (20) even if the test robot (10) moves along the same movement speed and movement path.

In the step (S140) of calculating the maximum speed of the test robot so that the sizes of the collision pressure and the collision force fall within the preset allowable safety criteria, if the sizes of the collision pressure (P) and the collision force (F _C ) are greater than the sizes of the preset maximum collision pressure (P _MAX ) and maximum collision force (F _MAX ), the maximum speed that satisfies the sizes of the collision pressure (P) and the collision force (F _C ) of the maximum collision pressure (P _MAX ) and the maximum collision force (F _MAX ) is calculated. That is, if the safety of the robot (R) is not secured, the maximum speed is calculated so that the sizes of the collision pressure (P) and the collision force (F _C ) fall within the sizes of the maximum collision pressure (P _MAX ) and the maximum collision force (F _MAX ).

In the step (S150) of resetting the movement time and movement path of the test robot, the profile information is modified so that the test robot (10) can move at the maximum speed calculated in the previous step (S140) to reset the movement time and movement path of the test robot (10).

This is because the force applied to the impacted body (20) varies depending on the speed of the test robot (10). That is, if the moving speed is reduced, the force applied to the impacted body (20) is reduced, and as the force applied to the impacted body (20) is reduced, the pressure is also reduced. Therefore, if the profile information is modified so that the test robot (10) can move at the maximum speed calculated in the previous step (S140), it becomes possible to implement a robot that does not cause injury to the human body while the test robot (10) is moving at the maximum speed.

As described above, the method for improving the safety of a robot can be obtained by simulating the size of the collision pressure and collision force applied to the collision target by the test robot. Since such a test robot is formed as a three-dimensional model robot or a three-dimensional image robot having a shape and driving motion similar to that of an actual robot, it is not necessary to have a separate device for obtaining the collision pressure, collision force, movement speed, etc. applied to the actual robot as in the past, so that a safety evaluation can be performed at a low cost.

In addition, by calculating the contact pressure applied to the collided body according to the shape of each part of the test robot to select the injury-causing risk part, and calculating the collision pressure and collision force applied to the collided body at the selected injury-causing risk part, it is possible to obtain the collision pressure and collision force corresponding to the shape of the test robot. That is, in the past, since the collision pressure and collision force applied to the collided body were calculated by constantly applying the contact pressure regardless of the shape of the robot, there was a disadvantage in that the accuracy of the calculated values was low. However, by calculating the contact pressure applied to the collided body according to the shape of each part of the test robot as in the present invention and selecting the injury-causing risk part through this value, it is possible to obtain the collision pressure and collision force corresponding to the shape of the collision part of the test robot, and thus the accuracy can be improved.

In addition, if the size of the impact pressure and collision force applied to the colliding body does not satisfy the safety evaluation criteria of the test robot, the posture of the test robot is controlled at regular intervals so that the size of the collision pressure and collision force satisfies the safety evaluation criteria, thereby improving the safety of the robot.

In addition, if the magnitude of the impact pressure and collision force applied to the colliding body does not satisfy the safety evaluation criteria of the test robot, the speed of the test robot is controlled to the maximum so that the magnitude of the collision pressure and collision force satisfies the safety evaluation criteria, so that the robot can move along the same movement path at the maximum speed while improving safety.

Fig. 6 is a drawing showing the size of the contact pressure applied to the impacted body according to the shape of each part of the test robot, and Fig. 7 is a drawing showing the values of the collision pressure and the collision force obtained through a 3D modeling program. Fig. 8 is a drawing showing the control state of the robot that maximizes productivity and safety through speed control, and Fig. 9 is a drawing showing the state in which the path is modified by setting the joint angle to maximize safety.

The process of a method for improving the safety of a robot is explained as follows with reference to FIGS. 1 to 9.

First, the user inputs shape information of an actual robot (R) into a simulation program to obtain a three-dimensional image test robot, or obtains a three-dimensional model test robot through a three-dimensional measurement sensor. Here, the test robot (10) may be formed by a manipulator capable of moving in at least one direction among the X-axis direction, the Y-axis direction, the Z-axis direction, the pitch direction, the yaw direction, and the roll direction. That is, the test robot (10) may be a manipulator having one or more degrees of freedom.

Then, profile information including movement time information and movement path information is input into the simulation program or robot system to set the movement time and movement path of the test robot (10). Accordingly, the test robot (10) performs a simulation in which it moves along the set movement path for a certain period of time.

And, according to the shape of each part of the test robot (10), the contact pressure applied to the impacted body (20) is calculated, and at least one injury-causing risk part of the test robot (10) is set through the calculated contact pressure value. This is because, as illustrated in FIG. 6, the size of the contact pressure applied to the impacted body (20) varies depending on the shape of each part of the robot. Here, the injury-causing risk part may be either the part having the largest value among the calculated contact pressures or the part whose contact pressure exceeds the preset value, but in this embodiment, the end effector (13) and the link (12) are described as the injury-causing risk parts.

When the risk of injury-causing portion of the robot is set in this way, the collision pressure (P) and the collision force (F _C ) applied to the colliding body (20) are calculated by considering the effective mass, movement speed, and direction of the risk of injury-causing portion of the robot (10). Here, the values of the collision pressure (P) and the collision force (F _{C ) applied to the colliding body (20) from the end effector (13) and link (12), which are the risk of injury-causing portions, can be expressed as shown in Fig. 7, and the method of calculating the values of the collision pressure (P) and the collision force (F C )} is as described above, so it will be omitted.

Once the sizes of the collision pressure (P) and the collision force (F _C ) are determined in this way, it is determined whether the determined collision pressure (P) and the collision force (F _C ) fall within the sizes of the preset maximum collision pressure (P _MAX ) and maximum collision force (F _MAX ). In other words, if the sizes of the collision pressure (P) and the collision force (F _C ) fall within the sizes of the preset maximum collision pressure (P _MAX ) and maximum collision force (F _MAX ), the robot (R) is determined to be safe, and conversely, if the sizes of the collision pressure (P) and the collision force (FC) are greater than the sizes of the maximum collision pressure (P _MAX ) and maximum collision force (F _MAX ), the robot (R) is determined to be unsafe. Here, the sizes of the preset maximum collision pressure (P _MAX ) and maximum collision force (F _MAX ) can be configured as sizes according to the International Organization for Standardization (ISO) standards.

If the robot (R) is judged to be unsafe, the joint angles of the test robot (10) are adjusted so that the sizes of the collision pressure (P) and the collision force (F _C ) of the test robot (10) fall within the sizes of the preset maximum collision pressure (P _MAX ) and maximum collision force (F _MAX ), as shown in FIG. 9, thereby changing the posture of the link part (12) and the end effector (13).

And, if the robot (R) is judged to be unsafe, the maximum speed of the test robot (10) is calculated so that the sizes of the collision pressure (P) and the collision force (F _C ) of the test robot (10) are within the sizes of the preset maximum collision pressure (P _MAX ) and the maximum collision force (F _MAX ), and the calculated maximum speed is re-input into the profile to control the speed of the test robot (10) (above, prior art 1).

FIG. 10 is a flowchart for explaining a safety evaluation method of a robot according to another embodiment of the present invention, and relates to a robot safety evaluation method including a technology for analyzing thermal hazards due to contact. As illustrated in FIG. 10, the safety evaluation method of a robot according to the present embodiment includes a step of acquiring shape information, mass information, and thermal information of a test robot (S310), a step of acquiring motion profile information of the test robot (S320), a step of calculating a physical quantity applied to a colliding body by considering the shape information, mass information, thermal information, and motion profile information of the test robot that are at risk of causing injury (S330), and a step of evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity (S340).

Here, the test robot has at least one joint, and the thermal information of the test robot includes at least one of temperature and thermal conductivity. The motion profile information of the test robot includes at least one of position, velocity, and acceleration of the joint at a single or multiple points in time, and the calculated physical quantity includes at least one of force, pressure, energy, and contact time. In the step S340 of evaluating safety, the safety is evaluated by comparing the calculated physical quantity with the size of the preset physical quantity.

A method for improving the safety of a robot according to another embodiment of the present invention further includes a step (S350) of modifying the motion profile information or proposing a modified motion profile based on the safety evaluated in step S340 of the flow chart of FIG. 10, thereby improving the safety or productivity of the robot.

The robot safety assessment and safety improvement method according to the present embodiment is a risk analysis technique for an object that causes damage to the human body due to heat when a person comes into contact with or approaches a thermal hazard source, and can analyze thermal risk by considering the temperature of the object, thermal conductivity, contact area according to shape, collision detection of the test robot at the time of collision, and contact time between the human body and the object considering the physical properties of the human body and the test robot.

Fig. 11 is a diagram for explaining thermal hazard according to contact time in the embodiment illustrated in Fig. 10. Referring to Fig. 11, contact time can be calculated only if there is injury-causing risk shape information, mass information, and motion profile information of the test robot. In addition, thermal hazard (e.g., burn) can be analyzed through contact time and thermal information (e.g., temperature).

Thermal hazard (e.g. burn) = f(contact time, temperature)

Here, the depth of the burn is determined by the temperature of the substance causing it and the time of contact with the skin. For example, at 55 degrees Celsius, 10 seconds of contact will cause deep second-degree burns, and at 60 degrees Celsius, 5 seconds of contact will cause deep second-degree burns. At 40 to 45 degrees Celsius, skin burns can occur after 1 to 2 hours of contact.

FIG. 12 is a flowchart for explaining a robot safety evaluation method by the shape of a basic unit according to another embodiment of the present invention. As illustrated in FIG. 12, the robot safety evaluation method according to the present embodiment includes a step of acquiring shape information and mass information of a test robot (S410), a step of acquiring shape information of the test robot as a single or combined shape of one or more basic units (S420), a step of acquiring motion profile information of the test robot (S430), a step of calculating a physical quantity applied to a colliding body by considering the injury-causing risk shape information, mass information, and motion profile information of the test robot (S440), and a step of evaluating the safety of the test robot by considering the magnitude of the calculated physical quantity (S450).

Here, the test robot has at least one joint. Step S420 directly inputs shape information of a single or combination of one or more basic units of the test robot or sets shape information of a previously acquired test robot by replacing it with the shape of the basic unit.

The motion profile information of the test robot includes at least one of the position, velocity, and acceleration of the joint at a single or multiple points in time, and the physical quantity includes at least one of force, pressure, energy, and contact time, and the step of evaluating safety (S450) evaluates safety by comparing the calculated physical quantity with the size of the preset physical quantity.

A method for improving robot safety according to another embodiment of the present invention further includes a step (S460) of modifying motion profile information or proposing a modified motion profile based on the safety evaluated in step S450 of the flow chart of FIG. 12, thereby improving the safety or productivity of the robot.

Meanwhile, since the collision force and pressure vary depending on the shape of the collision site, safety is evaluated by including shape information. However, since evaluating all shapes requires a lot of computing power, safety can be evaluated by substituting them with basic unit shapes. At this time, it is necessary to automatically match the unit shape to the shape of the robot, and FIG. 13 is a drawing schematically explaining a technology for automatically matching the unit shape to the shape of the robot in the present invention. As illustrated in FIG. 13, the drawing illustrated on the left is a blueprint of a robot that was obtained in advance, which largely includes an end effector and a gripper, and, for example, can be simplified into a cylindrical unit digitized with two different radii (R1, R3) and a hemispherical unit digitized with a radius R2, as illustrated on the right, using the cylinder function and the sphere function of AutoCAD.

FIG. 14 is a flowchart for explaining a safety evaluation method of a robot according to another embodiment of the present invention. As illustrated in FIG. 14, the safety evaluation method of a robot according to the present embodiment includes a step of obtaining mass information of a test robot (S510), a step of measuring basic information that can be configured through sensors and the like to obtain measurement information of the test robot through the sensors (S520), a step of replacing the already obtained basic information with shape information of two or more dimensions to obtain shape information based on the measurement information (S530), a step of obtaining motion profile information of the test robot (S540), a step of calculating a physical quantity applied to a colliding body by considering the shape information, mass information, and motion profile information of the test robot that poses a risk of injury (S550), and a step of evaluating the safety of the test robot by considering the size of the calculated physical quantity (S560).

In the above-described configuration, the step (S520) of acquiring robot shape measurement information can be performed through basic information that can be configured through a sensor, for example, a camera, for example, a photo or a video, and the step (S530) of acquiring shape information based on the measurement information can be performed by replacing the basic information acquired in step S520 with shape information of two or more dimensions, for example, a drawing or a STEP file.

Here, the test robot has at least one joint, and the measurement information includes two-dimensional or higher-dimensional data at a single or multiple points in time. The motion profile information of the test robot includes at least one of the position, velocity, and acceleration of the joint at a single or multiple points in time, and the calculated physical quantity includes at least one of force, pressure, energy, and contact time. The step of evaluating safety (S560) evaluates safety by comparing the calculated physical quantity with the size of the preset physical quantity.

A method for improving robot safety according to another embodiment of the present invention further includes a step (S570) of modifying motion profile information or proposing a modified motion profile based on the safety evaluated in step S560 of the flow chart of FIG. 14, thereby improving the safety or productivity of the robot.

Meanwhile, in this embodiment, shape information of the test robot is not directly input, but shape information can be calculated based on image information such as a photo or video of the test robot. Fig. 15 is a diagram for explaining a process of calculating shape information based on an image of a general test robot. As illustrated in Fig. 15, in this embodiment, an image of a general test robot, as exemplified in the upper left, is captured using a camera, for example, a camera of a smartphone, and shape information is calculated by processing this with an application program for a 3D scanner installed in the smartphone, thereby finally obtaining shape information as illustrated in Fig. 13.

FIG. 16 is a flowchart for explaining a safety evaluation method of a robot according to another embodiment of the present invention. As illustrated in FIG. 16, the safety evaluation method of a robot according to the present embodiment includes a step of acquiring shape information and mass information of a test robot (S610), a step of acquiring spatial information (S620), a step of acquiring motion profile information of the test robot (S630), a step of calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, motion profile information, and spatial information of the test robot (S640), and a step of evaluating the safety of the test robot by considering the size of the calculated physical quantity (S650).

Here, the test robot has at least one joint, and the spatial information includes at least one of a work area of the test robot, an inoperable area of the test robot, and an obstacle area. The motion profile information of the test robot includes at least one of a position, a velocity, and an acceleration of the joint at a single or multiple points in time, and the calculated physical quantity includes at least one of a force, a pressure, an energy, and a contact time. The step of evaluating safety (S650) evaluates safety by comparing the calculated physical quantity with the size of a preset physical quantity.

A method for improving robot safety according to another embodiment of the present invention further includes a step (S660) of modifying motion profile information or proposing a modified motion profile based on the safety evaluated in step S650 of the flow chart of FIG. 16, thereby improving the safety or productivity of the robot.

In the above-described configuration, spatial information is essential information for calculating physical quantities that take into account not only collisions between the robot and a person, but also human entrapment collisions between the robot and an obstacle, including obstacles within the robot's work area. This spatial information can be taken into account in the step (S660) of modifying the motion profile information or proposing a modified motion profile, including the robot's inoperable area.

FIG. 17 is a flowchart for explaining a robot safety evaluation method according to another embodiment of the present invention, which can be performed using a sensor-integrated risk judgment/control intelligent device as illustrated in FIG. 18, and includes a step of acquiring shape information and mass information of a test robot (S710), a step of acquiring measurement information of a sensor (S720), a step of acquiring motion profile information of the test robot (S730), a step of calculating a physical quantity applied to a colliding body by considering the injury-causing risk shape information, mass information, motion profile information, and measurement information through the sensor of the test robot (S740), and a step of evaluating the safety of the test robot by considering the size of the calculated physical quantity (S750).

Here, the test robot has at least one joint, and the measurement information is detection information of the sensor, and includes at least one of position information, velocity, and acceleration information of a human body or a body part recognized by the sensor. The motion profile information of the test robot includes at least one of position, velocity, and acceleration of the joint at a single or multiple points in time, and the calculated physical quantity includes at least one of force, pressure, energy, and contact time. The step of evaluating safety (S750) evaluates safety by comparing the calculated physical quantity with the size of the preset physical quantity.

A method for improving robot safety according to another embodiment of the present invention further includes a step (S760) of modifying motion profile information or proposing a modified motion profile based on the safety evaluated in step S750 of the flow chart of FIG. 17, thereby improving the safety or productivity of the robot.

Meanwhile, the sensor-integrated risk judgment/control intelligent device, in which the present embodiment is performed, obtains motion profile information from a test robot as illustrated in FIG. 18, and obtains measurement information from a sensor, for example, information including at least one of position information, velocity, and acceleration information of a human body or a body part recognized by the sensor as described above, to evaluate the safety of the robot, and based on this, performs calculations to improve safety and transmits modified motion profile information to the test robot to improve its safety.

As described above, while the present invention has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims (20)

A step of acquiring shape information, mass information and thermal information of a test robot; Step of acquiring motion profile information of a test robot; Step for calculating the physical quantity applied to the impacted body by considering the shape information, mass information, thermal information, and motion profile information of the test robot that causes injury; and A method for evaluating the safety of a robot, comprising a step of evaluating the safety of a test robot by considering the size of the above-mentioned calculated physical quantity. In claim 1, The test robot has at least one joint, The thermal information of the test robot includes at least one of temperature and thermal conductivity. The motion profile information of the test robot includes at least one of the position, velocity and acceleration of the joint at a single or multiple points in time, The above-mentioned calculated physical quantity includes at least one of force, pressure, energy, contact time and heat energy, The step of evaluating the above safety is a safety evaluation method of a robot in which safety is evaluated by comparing the calculated physical quantity with the size of a preset physical quantity. A step of acquiring shape information, mass information and thermal information of a test robot; Step of acquiring motion profile information of a test robot; A step of calculating a physical quantity applied to a collision target by considering injury-causing risk shape information, mass information, thermal information, and motion profile information of a test robot; A step for evaluating the safety of the test robot by considering the size of the above-mentioned calculated physical quantity, and A method for improving the safety of a robot, comprising a step of modifying motion profile information or proposing a modified motion profile based on the evaluated safety. In claim 3, The test robot has at least one joint, The thermal information of the test robot includes at least one of temperature and thermal conductivity. The motion profile information of the test robot includes at least one of the position, velocity and acceleration of the joint at a single or multiple points in time, The above-mentioned calculated physical quantity includes at least one of force, pressure, energy, contact time and heat energy, The step of evaluating the above safety evaluates safety by comparing the calculated physical quantity with the size of the preset physical quantity. A method for improving the safety of a robot equipped to increase safety or productivity, wherein the step of modifying the above motion profile information or proposing a modified motion profile is provided. Step of acquiring mass information of a test robot; A step of acquiring shape information of a test robot as a single or combination of shapes of one or more basic units; Step of acquiring motion profile information of a test robot; Step for calculating the physical quantity applied to the impacted body by considering the injury-causing risk shape information, mass information, and motion profile information of the test robot; and A method for evaluating the safety of a robot, comprising a step of evaluating the safety of a test robot by considering the size of the above-mentioned calculated physical quantity. In claim 5, The test robot has at least one joint, The shape information of a test robot of a single or combination of one or more basic units is directly input by the user, or is set by replacing the shape information of the previously acquired test robot with the shape of the basic unit. The motion profile information of the test robot includes at least one of the position, velocity and acceleration of the joint at a single or multiple points in time, The above physical quantity includes at least one of force, pressure, energy and contact time, The step of evaluating the above safety is a safety evaluation method of a robot in which safety is evaluated by comparing the calculated physical quantity with the size of a preset physical quantity. Step of acquiring mass information of a test robot; A step of acquiring shape information of a test robot as a single or combination of shapes of one or more basic units; Step of acquiring motion profile information of a test robot; A step of calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, and motion profile information of a test robot; A step for evaluating the safety of the test robot by considering the size of the above-mentioned calculated physical quantity, and A method for improving the safety of a robot, comprising a step of modifying motion profile information or proposing a modified motion profile based on the evaluated safety. In claim 7, The test robot has at least one joint, Information on the shape of a test robot of a single or combination of one or more basic units is directly input by the user, or is set by replacing the shape information of the test robot that has already been acquired with the shape of the basic unit. The motion profile information of the test robot includes at least one of the position, velocity and acceleration of the joint at a single or multiple points in time, The above physical quantity includes at least one of force, pressure, energy and contact time, The step of evaluating the above safety evaluates safety by comparing the calculated physical quantity with the size of the preset physical quantity. A method for improving the safety of a robot equipped to increase safety or productivity, wherein the step of modifying the above motion profile information or proposing a modified motion profile is provided. Step of acquiring mass information of a test robot; A step of obtaining measurement information of a test robot by measuring basic information that can be configured through a sensor; A step of obtaining shape information by replacing the above measurement information with shape information of two or more dimensions; Step of acquiring motion profile information of a test robot; Step for calculating the physical quantity applied to the impacted body by considering the injury-causing risk shape information, mass information, and motion profile information of the test robot; and A method for evaluating the safety of a robot, comprising a step of evaluating the safety of a test robot by considering the size of the above-mentioned calculated physical quantity. In claim 9, The test robot has at least one joint, Measurement information includes two-dimensional or more data at single or multiple points in time. The motion profile information of the test robot includes at least one of the position, velocity and acceleration of the joint at a single or multiple points in time, The above-mentioned calculated physical quantity includes at least one of force, pressure, energy and contact time, The step of evaluating the above safety is a safety evaluation method of a robot in which safety is evaluated by comparing the calculated physical quantity with the size of a preset physical quantity. Step of acquiring mass information of a test robot; A step of obtaining measurement information of a test robot by measuring basic information that can be configured through a sensor; A step of obtaining shape information by replacing the above measurement information with shape information of two or more dimensions; Step of acquiring motion profile information of a test robot; A step of calculating a physical quantity applied to a colliding body by considering injury-causing risk shape information, mass information, and motion profile information of a test robot; A step for evaluating the safety of the test robot by considering the size of the above-mentioned calculated physical quantity, and A method for improving the safety of a robot, comprising a step of modifying motion profile information or proposing a modified motion profile based on the evaluated safety. In claim 11, The test robot has at least one joint, Measurement information includes two-dimensional or more data at single or multiple points in time. The motion profile information of the test robot includes at least one of the position, velocity and acceleration of the joint at a single or multiple points in time, The above-mentioned calculated physical quantity includes at least one of force, pressure, energy and contact time, The step of evaluating the above safety evaluates safety by comparing the calculated physical quantity with the size of the preset physical quantity. A method for improving the safety of a robot equipped to increase the safety or productivity, wherein the step of modifying the above motion profile information or proposing a modified motion profile is provided. Step of acquiring shape information and mass information of a test robot; Step of obtaining spatial information; Step of acquiring motion profile information of a test robot; Step for calculating the physical quantity applied to the impacted body by considering the shape information, mass information, motion profile information, and spatial information of the test robot that causes injury; and A method for evaluating the safety of a robot, comprising a step of evaluating the safety of a test robot by considering the size of the above-mentioned calculated physical quantity. In claim 13, The test robot has at least one joint, The above spatial information includes at least one of a work area of the test robot, an inoperable area of the test robot, and an obstacle area. The motion profile information of the test robot includes at least one of the position, velocity and acceleration of the joint at a single or multiple points in time, The above-mentioned calculated physical quantity includes at least one of force, pressure, energy and contact time, The step of evaluating the above safety is a safety evaluation method of a robot in which the safety is evaluated by comparing the calculated physical quantity with the size of the preset physical quantity. Step of acquiring shape information and mass information of a test robot; Step of obtaining spatial information; Step of acquiring motion profile information of a test robot; A step of calculating a physical quantity applied to a colliding body by considering the shape information, mass information, motion profile information, and spatial information of the test robot that causes injury; A step for evaluating the safety of the test robot by considering the size of the above-mentioned calculated physical quantity, and A method for improving the safety of a robot, comprising a step of modifying motion profile information or proposing a modified motion profile based on the evaluated safety. In claim 15, The test robot has at least one joint, The above spatial information includes at least one of a work area of the test robot, an inoperable area of the test robot, and an obstacle area. The motion profile information of the test robot includes at least one of the position, velocity and acceleration of the joint at a single or multiple points in time, The above-mentioned calculated physical quantity includes at least one of force, pressure, energy and contact time, The step of evaluating the above safety evaluates safety by comparing the calculated physical quantity with the size of the preset physical quantity. A method for improving the safety of a robot equipped to increase safety or productivity by utilizing the spatial information, wherein the step of modifying the above motion profile information or proposing a modified motion profile is performed. Step of acquiring shape information and mass information of a test robot; A step of acquiring measurement information of a sensor; Step of acquiring motion profile information of a test robot; A step for calculating the physical quantity applied to the impacted body by considering the injury-causing risk shape information, mass information, motion profile information, and the above measurement information of the test robot; and A method for evaluating the safety of a robot, comprising a step of evaluating the safety of a test robot by considering the size of the above-mentioned calculated physical quantity. In claim 17, The test robot has at least one joint, The above measurement information includes at least one of a sensor's detection signal, position, velocity and acceleration information of a person's body or body part recognized by the sensor, The motion profile information of the test robot includes at least one of the position, velocity and acceleration of the joint at a single or multiple points in time, The above-mentioned calculated physical quantity includes at least one of force, pressure, energy and contact time, The step of evaluating the above safety is a safety evaluation method of a robot in which the safety is evaluated by comparing the calculated physical quantity with the size of the preset physical quantity. Step of acquiring shape information and mass information of a test robot; A step of acquiring measurement information of a sensor; Step of acquiring motion profile information of a test robot; A step of calculating a physical quantity applied to a colliding body by considering the injury-causing risk shape information, mass information, motion profile information, and the above measurement information of the test robot; A step for evaluating the safety of the test robot by considering the size of the above-mentioned calculated physical quantity, and A method for improving the safety of a robot, comprising a step of modifying motion profile information or proposing a modified motion profile based on the evaluated safety. In claim 19, The test robot has at least one joint, The above measurement information includes at least one of sensor detection information, position, velocity and acceleration information of a person's body or body part recognized by the sensor, The motion profile information of the test robot includes at least one of the position, velocity and acceleration of the joint at a single or multiple points in time, The above-mentioned calculated physical quantity includes at least one of force, pressure, energy and contact time, The step of evaluating the above safety is to evaluate the safety by comparing the calculated physical quantity with the size of the preset physical quantity. A method for improving the safety of a robot equipped to increase the safety or productivity, wherein the step of modifying the above motion profile information or proposing a modified motion profile is provided.

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