WO2014005607A1

WO2014005607A1 - Robot-motion-input-device

Info

Publication number: WO2014005607A1
Application number: PCT/EP2012/002861
Authority: WO
Inventors: Björn MATTHIAS; Hao Ding
Original assignee: ABB Technology AG
Current assignee: ABB Technology AG
Priority date: 2012-07-06
Filing date: 2012-07-06
Publication date: 2014-01-09
Anticipated expiration: 2015-01-06

Description

Robot-Motion-Input-Device

Description

The invention relates to a robot-position-input-device for a robot having at least seven degrees of freedom in motion, whereas a device-output with a related output signal is provided for each degree of freedom in movement.

It is known that manipulators such as robots provide several degrees of freedom in movement. A typical robot arm comprises a chain of manipulator segments with a connecting revolute joint in between, wherein each revolute joint represents one degree of freedom in movement. At the end of the robot arm normally the tool center point (TCP) is located. A tool center point is the reference point for the whole movement of the robot. A tool center point has not necessarily to be related to a physical point on the robot, it can also be a virtual point. Each manipulator segment with related revolute joint is normally driven by a dedicated drive. But it is also possible not to have a revolute joint with manipulator segment for performing a swiveling movement but a prismatic joint respectively a manipulator segment on a linear axis for performing a linear movement thereon. Also a combination of both is possible.

Anyhow, six degrees of freedom in movement allow reaching of each coordinate within the working range of the robot, namely x, y, z in Cartesian coordinates, in each orientation, namely Ry, Ry, Rz in Cartesian coordinates. Adding additional degrees of freedom in movement provides a redundancy in the ways in which the given Cartesian position and orientation can be reached. Thus, it is possible to reach each coordinate within the working range of the robot in each orientation with different configurations of the robot arm. This is useful for example to have alternative configura- tions for avoiding possible collisions with other objects or even robots, which are at least in part in the same working range of the robot.

For teaching or even refining a movement program of a robot, a robot-position-input- device is required, which might be integrated in a teach pendant, for example. A robot movement program typically comprises a sequence of coordinates with associated orientation. During execution of the program, the robot performs a movement along those coordinates. While generating or refining such a movement program, the robot is manually moved to the coordinates of interest and the coordinate data are adapted. The position and orientation of the robot is fine-tuned by using the robot- position-input-device and afterwards the thus determined coordinates are transferred to the robot or its controller.

A robot-position-input-device is a manual interface which allows the operator to manually determine the position or the orientation of the robot arm. Here devices such as a joystick with typically three degrees of freedom in movement or a 6D mouse with six degrees of freedom in movement are known.

Disadvantageous within the state of the art is that, on the one side, such devices are either not provided for the determination of a coordinate for a robot with a redundant seventh or higher degree of freedom in movement. On the other side, such devices that allow the input of a coordinate for a robot with seven degrees of freedom in movement are rather complex and thus heavy-weight. Thus, the extended use of such a device is fatiguing for an operator holding it.

Based on this state of the art it is the objective of the invention to provide a robot- position-input-device, which is on one side light-weight and easily allows the teaching of a position of a robot with seven or more degrees of freedom in movement.

This problem is solved by a robot-position-input-device of the aforementioned kind. This is characterized in that it further comprises

• an input-device-module for manual tuning of at least two degrees of freedom in movement, wherein a module-output with a related output signal is provided for each degree of freedom in movement, • at least one first-selector-switch for selectively connecting the module-outputs with related device-outputs,

wherein each device-output is selectively connectable with one of the module-outputs by applying at least one of the selector-switch settings.

The basic idea of the invention consists in providing a light-weight input-device- module for a lower number than the required number of degrees of freedom in movement and further to provide a light-weight selector-switch, which allows the selective connection of the module-outputs to the device-outputs. While generating or fine-tuning a robot program, the operator normally does not use all seven or more degrees of freedom in movement at the same time. Moreover, he typically uses only several groups of degrees of freedom in movement at the same time. Thus, it is possible to combine groups of degrees of freedom which typically are used together. By foreseeing selector-switch such groups are selectively activatable and a light-weight and easily usable robot-position-input-device for a robot with seven or more degrees of freedom in movement is provided.

A selector-switch has on the one side a manual switchable component. Additionally, a connection component is provided, which can consist in the easiest case of a set of mechanical driven contacts, but also of some electronic connection components. Several types of selector-switches are thinkable, for example a single switch with different mode positions or some different switches which are interlocked each to each other.

The output signals of the module-outputs and the device-outputs might be analog signals, for example a certain voltage level corresponding to a certain position of the associated degree of freedom in movement. But also digital values are suitable kinds of output signals.

In a variant of the invention, the robot-position-input-device comprises a transformation device to adapt the signals of the module-outputs to the associated requirements of the device-outputs. Such a transformation device is for example useful for adapting the signal level of the belonging output signals or convert for example an analog signal into a digital signal. Thus, it is also possible alternatively to provide output signals according to different kinds of coordinate systems. In this case the transformation device comprises the relevant transformation algorithms.

According to a further variant of the invention, the robot-position-input-device comprises a communication interface for providing the signals of the device outputs respectively the belonging values to an external device. Such a communication interface corresponds typically to common communication standards and is for example designed to have a USB output for further connection. But also a wireless connection is within the scope of the invention.

According to a further embodiment of the robot-position-input-device it is foreseen to provide signals at its device-outputs, which correspond either to Cartesian coordinates, that is to say at least x, y, z, Rx, Ry, Rz, 7^th degree of freedom, or to joint coordinates, that is to say at least J1 , J2, J3, J4, J5, J6, J7, or to further coordinate systems such as spherical or cylindrical. Depending on the coordinate to be fine-tuned or programmed, it might be either more comfortable to use Cartesian coordinates or joint coordinates. If one joint in joint coordinates is selected, only the associated manipulator segment related to this joint is moved when a coordinate is adjusted. In Cartesian coordinates several joints might be moved at the same time when for example only the x-coordinate is selected and adjusted. Thus, the operator has a comfortable choice with which coordinate system he wants to work. In the case of several coordinate systems a switch is provided for the selection among them.

According to another embodiment of the invention the robot-position-input-device has exactly seven active device-outputs and is designed for a robot with seven degrees of freedom in movement therewith. Normally, one redundant degree of freedom in movement is sufficient for providing enough configuration variations of the robot arm to reach a certain coordinate in a certain orientation. Thus, those positions of robot which might cause collisions can be avoided by choosing another configuration of the robot arm.

In a preferred embodiment of the invention, the input-device-module has exactly three active module-outputs and the signals of these module-outputs correspond - depending on the current setting of the first-selector-switch - to one of (x, y, z), (Rx, Ry, Rz), 7^th degree of freedom, (J1 , J2, J3), (J4, J5, J6), J7. Those groups of degrees of freedom in movement are typically used together by the operator, thus they are very suitable to be controlled at the same time by the input-device-module without any loss of comfort for the operator. The first-selector-switch covers as well the choice if a Cartesian or a joint coordinate system shall be chosen as well as the choice of which group of degrees of freedom in movement shall be activated. The number of switches is reduced thereby.

Following another embodiment of the invention, the robot-position-input-device comprises at least one second separated selector-switch for independently switching between Cartesian and joint coordinate output mode. This enables an easy selection between the available output modes.

According to a further preferred embodiment of the invention, the input-device- module has exactly three active module-outputs wherein the signals of these module- outputs correspond - depending on the current setting of the first and the second selector-switches - either to one of (x, y, z), (Rx, Ry, Rz), 7^th degree of freedom or to one of (J1 , J2, J3), (J4, J5, J6), J7. In both coordinate systems there is a group for the main coordinate, another group for the orientation and a third group for the 7^th degree of freedom. In the case of the 7^th degree of freedom only one of the three degrees of freedom in movement of the input-device-module is used. The other two are either not used or also linked to the 7^th degree of freedom. This is also a variant to combine groups of degrees of freedom in movement which is comfortable for the operator since those groups are typically used together.

According to another preferred embodiment of the robot-position-input-device the input-device-module has exactly two active module-outputs and the signals of those module-outputs correspond - depending on the current setting of the first and the second-selector-switches - either to one of (x, Rx), (y, Ry), (z, Rz), 7^th degree of freedom or to one of (J1 , J2), (J3, J4), (J5, J6), J7. The use of an input-device-module with only two degrees of freedom in movement makes it extremely light-weight and easy to handle. According to a further embodiment of the invention, the robot-position-input-device comprises a third selector-switch for enabling. This is useful to prevent an unintended setting or modification of a coordinate or an orientation.

Following another embodiment of this invention, the input-device-module is constructed joystick-like. A joystick is a well-known and proven input-device-module for two or three degrees of freedom in movement. According to another embodiment, the robot-position-input-device comprises means for magnetic attachment. Thus, it is easily attachable for example to a robot or to the tip of a robot arm near the TCP point. This enables a very easy and comfortable determination of a coordinate and/or its orientation, since there is an immediate feedback to the manual use of the robot- position-input-device by the movement of the robot itself.

According to another embodiment of the invention, the robot-position-input-device is integrated into a teach pendant of a robot. Due to the light-weight structure of such a device, the overall weight of a teach pendant is also reduced therewith in an advantageous way.

The use of a robot-position-input-device according to the invention for teaching a robot will facilitate the teaching process in an advantageous way.

Further advantageous embodiments of the invention are mentioned in the dependent claims.

The invention will now be further explained by means of an exemplary embodiment and with reference to the accompanying drawings, in which:

Figure 1 shows an exemplary first robot-position-input-device in a structural view,

Figure 2 shows an exemplary second robot-position-input-device,

Figure 3 shows an exemplary third robot-position-input-device and

Figure 4 shows an exemplary robot with seven degrees of freedom in movement.

Fig. 1 shows an exemplary first robot-position-input-device in a structural view 10. An exemplary input-device-module 12 is provided as a manual interacting device for tun- ing of three degrees of freedom in movement. The associated signals, either analog or digital, are provided at the module-outputs 14, 16 and from there to a selector- switch 18. The selector-switch 18 provides four different switch settings 22, 24, 26, 28, which alternatively can be selected, as indicated with the dotted lines 20.

Dependent on the currently selected switch setting 22, 24, 26, 28, the three module outputs 14, 16 are connected group-wise with one of seven device outputs 38, 40, 42. Which group is connected with which device outputs 38, 40, 42 is determined by the relation as indicated with the reference number 30 respectively with the connections 32, 34, 36. Thus, it is possible for example to connect the three module-outputs of a joystick in a first-selector-switch setting with the x, y, z device-outputs for coordinates, in a second-selector-switch setting with the Rx, Ry, Rz device-outputs for the orientation and in a third selector-switch setting with the 7^th degree of freedom.

Fig. 2 shows an exemplary second robot-position-input-device 50 in a 3D view. A cylindrical base body 52 comprises at its lower end magnetic means 54 for attachment, e.g. a magnet which is suitable to magnetically mount the robot-position-input- device 50 on the arm of a robot, for example. On the other side of the base body 52 an input device module 68, in this case a three dimensional joystick, is provided for tuning of three degrees of freedom in movement. The three movement directions or degrees of freedom in movement are indicated with the arrows with the reference number 69.

The base body 52 further comprises three first-selector-switches 56, 58, 60 which are interlocked each to each other and which determine the relation of the three degrees of freedom in movement to the device outputs, which are not shown in this Figure. Two second-selector-switches 62, 64 are provided to change between an output in Cartesian coordinates or an output in joint coordinates. A third selector-switch 66 is provided for enabling the robot-position-input-device 50.

Fig. 3 shows an exemplary third robot-position-input-device 70 in a 3D view. A cylindrical base body 72 comprises at its lower end magnetic means 74 for attachment, e.g., a magnet which is suitable to magnetically mount the robot-position-input-device 70 on the arm of a robot. On the other side of the base body 72 an input device module 88, in this case a two dimensional joystick, is provided for tuning of two degrees of freedom in movement. The three movement directions or degrees of freedom in movement are indicated with the arrows with the reference number 90. Furthermore, the input device module 88 is able to be pushed in the axial direction as indicated with the arrow 92. In this case a pushing in this direction enables the device 70.

The base body 72 further comprises four first-selector-switches 76, 78, 80, 82 which are interlocked each to each other and which determine the relation of the two degrees of freedom in movement to the device outputs, which are not shown in this Figure. Two second-selector-switches 84, 86 are provided to change between an output in Cartesian coordinates or an output in joint coordinates.

Fig. 4 shows an exemplary robot 100 with seven degrees of freedom in movement. The robot comprises seven revolute joints J1 , J2, J3, J4, J5, J6, J7 with associated manipulator segments, which are pivotable around the connected joint. Joints J1 , J2, J3 are provided to reach a belonging coordinate and joints J4, J5, J6 are provided for adjusting the orientation of the robot tip or the TCP. Joint J7 is also provided to reach a certain coordinate, thus J7 provides a redundancy in the degrees of freedom in movement of the robot.

List of reference signs exemplary first robot-position-input-device in a structural view exemplary first input-device-module

first module-output

second module-output

exemplary first-selector-switch

activation of switch setting

first-selector-switch setting

second-selector-switch setting

third seiector-switch setting

fourth selector-switch setting

relation to device-outputs

first connection

second connection

third connection

first device-output

second device-output

third device-output

communication interface

output of communication interface

exemplary second robot-position-input-device

base body

means for magnetic attachment

first first-selector-switch

second first-selector-switch

third first-selector-switch

first second-selector-switch

second second-selector-switch

third selector-switch

exemplary second input-device-module

three degrees of freedom in movement

exemplary third robot-position-input-device 72 base body

74 means for magnetic attachment

76 first first-selector-switch

78 second first-selector-switch

80 third first-selector-switch

82 fourth first-selector-switch

84 first second-selector-switch

86 second second-selector-switch

88 exemplary third input-device-module

90 three degrees of freedom in movement

92 movement for enabling robot-position-input-device

100 exemplary robot with seven degrees of freedom in movement

Claims

1. Robot-position-input-device (10, 50, 70) for a robot (100) having at least seven degrees of freedom in motion, whereas a device-output (38, 40, 42) with a related output signal is provided for each degree of freedom in movement,

characterized in that

it further comprises

• an input-device-module (12, 68, 88) for manual tuning of at least two degrees of freedom in movement (69, 90), wherein a module-output (14, 16) with a related output signal is provided for each degree of freedom in movement (69, 90),

• at least one first-selector-switch (18, 56, 58, 60, 76, 78, 80, 82) for selectively connecting the module-outputs (14, 16) with related device-outputs (38, 40, 42),

wherein each device-output (38, 40, 42) is selectively connectable with one of the module-outputs (14, 16) by applying at least one of the selector-switch settings (22, 24, 26, 28).

2. Robot-position-input-device according to claim 1 , characterized in that it comprises a transformation device to adapt the signals of the module-outputs (14, 16) to the belonging requirements of the device-outputs (38, 40, 42).

3. Robot-position-input-device according to claim 1 or claim 2, characterized in that it comprises a communication interface (44) for providing the signals of the device outputs (38, 40, 42) or the belonging values to an external device.

4. Robot-position-input-device according to any of the preceding claims, characterized in that it is foreseen to provide signals at its device-outputs (38, 40, 42), which correspond either to Cartesian coordinates, that is to say at least x, y, z, Rx, Ry, Rz, 7^th degree of freedom, or to joint coordinates, that is to say at least J1 , J2, J3, J4, J5, J6, J7, or to further coordinate systems such as spherical or cylindrical.

5. Robot-position-input-device according to claim 4, characterized in that it has exactly seven active device-outputs (38, 40, 42).

6. Robot-position-input-device according to claim 5, characterized in that the input- device-module has exactly three active module-outputs and in that the signals of those module-outputs correspond - depending on the current setting of the first- selector-switch (18, 56, 58, 60, 76, 78, 80, 82) - to one of (x, y, z), (Rx, Ry, Rz), 7^th degree of freedom, (J1 , J2, J3), (J4, J5, J6), J7.

7. Robot-position-input-device according to any of the claims 4 or 5, characterized in that it comprises at least one second-selector-switch (62, 64, 84, 86) for switching between Cartesian and joint coordinate output modes.

8. Robot-position-input-device according to claim 7, characterized in that the input- device-module (12, 68, 88) has exactly three active module-outputs and in that the signals of those module-outputs correspond - depending on the current setting of the first (18, 56, 58, 60, 76, 78, 80, 82) and the second (62, 64, 84, 86) selector-switch - either to one of (x, y, z), (Rx, Ry, Rz), 7^th degree of freedom or to one of (J1 , J2, J3), (J4, J5, J6), J7.

9. Robot-position-input-device according to claim 7, characterized in that the Input- device-module has exactly two active module-outputs (14, 16) and in that the signals of those module-outputs (14, 16) correspond - depending on the current setting of the first (18, 56, 58, 60, 76, 78, 80, 82) and the second (62, 64, 84, 86) selector-switch - either to one of (x, Rx), (y, Ry), (z, Rz), 7^th degree of freedom or to one of (J1 , J2), (J3, J4), (J5, J6), J7.

10. Robot-position-input-device according to any of the preceding claims, characterized in that it comprises a third selector-switch (66, 92) for enabling.

11. Robot-position-input-device according to any of the preceding claims, characterized in that the input-device-module is constructed joystick-like.

12. Robot-position-input-device according to any of the preceding claims, characterized in that it comprises means for magnetic attachment (54, 74).

13. Robot-position-input-device according to any of the preceding claims, characterized in that it is attached to robot (100).

14. Robot-position-input-device according to any of the preceding claims, characterized in that it is integrated into a teach pendant of a robot (100).

15. Use of a robot-position-input-device according to any of the proceeding claims for teaching and/or hand-guiding a robot (100).