CN103728057A - Ultrahigh-accuracy force sensor - Google Patents

Abstract

The ultra-high-precision force sensor involved in the invention belongs to the field of mechanical measurement. It is mainly composed of lever, armature, electromagnet, electromagnet bracket, support column, rotating mechanism, lever balance detection device, bottom plate, closed-loop control system, etc.: the armature is connected to the lever through screws, and the lever is installed on the rotating mechanism; under the armature It is an electromagnet, which is installed on the electromagnet support; the support column is fixed at the rear end of the lever and can move together with the lever, and the lever balance detection device is located below it; when the pressure acts on the sensor, the lever rotates, and the lever is balanced The detection device, and then through the closed-loop control system, make the electromagnet generate electromagnetic force, absorb the armature and return the lever to the initial position; since the mechanical structure of the sensor has not changed after the lever returns to the initial position, and the output of the sensor is the electromagnet control electric In the form of parameters, the control voltage can reach tens of volts, so the sensor can achieve ultra-high precision.

Description

Ultra High Precision Force Sensor

technical field

The invention relates to an ultra-high-precision force sensor, which belongs to the field of mechanical measurement.

technical background

As we all know, traditional force sensors include resistance strain gauges, semiconductor strain gauges, piezoresistive, piezoelectric and other types. The quantity is converted into an electrical signal, reflecting the size of the corresponding force. This measurement principle has limitations. Due to the reasons of elastic sensitive components and structural characteristics, the linearity is difficult to exceed one ten-thousandth. Due to the limitation of the linearity of the force sensor in this aspect, although the force sensor has developed rapidly in many methods and the technology is becoming more and more mature for a long time, the basic technical indicators such as linearity and accuracy have stagnated for a long time and cannot break through 100,000. The linearity of several, ultra-high-precision force sensors have not been able to make substantial progress, which has affected the development of technologies such as mass centroid measurement.

At present, the linearity of the traditional force sensor based on strain gauge technology is less than 0.3%, and the measurement accuracy is difficult to exceed 0.03%. The force sensor is the core component of the object mass centroid measurement equipment, and the accuracy of the sensor determines the measurement accuracy.

Contents of the invention

In order to overcome the disadvantages that the linearity of the traditional force sensor based on the strain technology is lower than 0.3%, and the measurement accuracy is difficult to exceed 0.03%, the invention provides an ultra-high precision force sensor that can improve the linearity and precision.

In order to achieve the above object, design of the present invention is:

Try to use a compensation force to offset the force on the ultra-high precision pressure sensor, and this compensation force can be generated by an electromagnet; as we all know, the electromagnetic force on an electromagnet can be reduced by changing the magnitude of the current flowing through it. control, and the current can be controlled by voltage. When a force acts on the ultra-high-precision pressure sensor, a detection device is used to detect the displacement and deformation of the sensor, and a closed-loop control system is used to control the current flowing through the electromagnet, so that the electromagnetic The force is just equal to the force acting on the sensor, so that the sensor returns to the state before deformation, so as long as the linearity of the control voltage can be guaranteed, the linearity of the ultra-high-precision sensor can be guaranteed, which is equivalent to transferring the linearity to the control voltage.

In order to achieve above-mentioned inventive concept, technical scheme of the present invention is:

An ultra-high-precision force sensor includes a lever, an electromagnet, an electromagnet support, an armature, a support column, a rotating mechanism, a lever balance detection device, a closed-loop control system, a base plate and other components. The armature is connected to the lever, the lever is placed on the rotating mechanism, and the rotating mechanism is fixed on the bottom plate. When the lever is horizontal, the electromagnet is placed directly under the armature, and the electromagnet is fixed on the electromagnet support, and the electromagnet support is fixed on the bottom plate. superior. In order to detect whether the lever returns to the initial position, the present invention adopts a lever balance detection device, adopts a pressure sensor, and other sensors can also be used, and the lever balance detection device is placed under the pressure end of the lever.

The positive effect of the present invention is:

1. Solve the contradiction between the range and linearity of traditional sensors. After the restoring force is applied, the mechanical structure of the ultra-high-precision sensor is exactly the same as before loading, the mechanical nonlinearity is completely eliminated, and the sensor itself is completely linear. Compared with the strain measurement sensor, it depends on the elastic sensitive element The deformation of , which is inherently nonlinear. 2. The anti-interference ability of the sensor is stronger. The output of the sensor appears in the form of an electromagnet controlling the electrical parameters. The control voltage can be as high as tens of volts. Through the relationship between the control voltage and the generated electromagnetic force, the magnitude of the measurement force can be obtained. Since the control voltage is much higher than the noise of the electronic device, it can be A high sensor accuracy is obtained.

Description of drawings

Figure 1 is a schematic diagram of an ultra-high precision force sensor;

Fig. 2 is a schematic diagram of a support column;

Fig. 3 is a schematic diagram of a lever balance detection device;

Fig. 4 is the schematic diagram that lever cooperates with rotating mechanism;

Fig. 5 is a schematic diagram of an electromagnet;

Detailed ways

The present invention will be further described through specific embodiments below, not limited to this embodiment, and simple transformation or equivalent application also belongs to the protection scope of the present invention.

An ultra-high-precision force sensor mainly includes a lever 1, an armature 2, an electromagnet 3, an electromagnet support 4, a support column 5, a rotating mechanism 6, a lever balance detection device 7, a base plate 8, a closed-loop control system, and the like. As shown in Figure 1, the armature 2 is connected to the front end of the lever 1 by screws, and the electromagnet 3 is directly below it; the electromagnet 3 is installed on the electromagnet bracket 4, and the electromagnet bracket 4 is fixed on the bottom plate 8 with screws; The whole lever 1 is also fixed on the base plate 8 with screws through the rotating mechanism 6; the support column 5 is installed at the end of the lever 1, and the lever balance detection device 7 is located below it. Fig. 2 is a schematic diagram of the support column 5, which is used to transmit pressure. Fig. 3 is a schematic diagram of the work of the lever balance detection device 7. In this example, a pressure sensor is used to detect whether the lever rotates and returns to the original equilibrium position. Since the support column 5 is fixed together with the lever 1 through the nut 9, when When the upper end of the support column 5 is under pressure, the end of the lever 1 will sink, and when the end of the lever 1 returns to its original position, the support column 5 will also return to its original position together; the lower end of the support column 5 passes through the steel ball 10, and after passing The sensor pressure head 11 transmits the pressure to the pressure sensor in the lever balance detection device 7 . What Fig. 4 shows schematically is how lever 1 and rotating mechanism 6 cooperate, and rotating mechanism 6 is mainly made up of rotating shaft bearing gland 13, rolling bearing 14, rotating shaft 15 and rotating shaft supporting 16, so lever 1 can rotate around rotating shaft 15. During specific implementation, when the support column 5 is under pressure, the end of the lever 1 will sink around the rotating shaft 15. At this time, the same amount of power will also act on the pressure sensor in the lever balance detection device 7. According to the pressure sensor measurement According to the size of the pressure, through the closed-loop control system, according to the obtained pressure, change the current flowing through the electromagnet 3, so that the generated electromagnetic force can just make the lever 1 return to the force before; then through the closed-loop control system, By converting the current flowing through the electromagnet into a pressure parameter, the pressure acting on the support column 5 can be obtained.

Claims (6)

1. A new type of ultra-high-precision force sensor, mainly composed of a lever 1, an armature 2, an electromagnet 3, an electromagnet support 4, a support column 5, a rotating mechanism 6, a lever balance detection device 7, a base plate 8, and a closed-loop control system and other components, characterized in that: the lever 1 is fixed 6 on the bottom plate 8 through the rotating mechanism, and can rotate around the rotating mechanism 6, the front end of the lever 1 is connected with the armature 2, and the lever 1 can be rotated around by absorbing the armature 2 through the electromagnet 3 The mechanism 6 rotates, and the support column 5 cooperates with the end of the lever 1 to bear the pressure. Through the lever balance device 7, it can be detected whether the lever 1 returns to the initial position, so as to control the electromagnetic force of the electromagnet 3 through the closed-loop system. Return lever 1 to its original position. 2. The ultra-high precision force sensor according to claim 1, characterized in that: the size of the lever 1 can be adjusted according to actual needs. 3. The ultra-high-precision force sensor as claimed in claim 1, characterized in that: said rotating lever balance detection device 7 can be composed of a pressure sensor, a displacement sensor or any other sensor capable of detecting whether the lever returns to its original position . 4. The ultra-high-precision force sensor according to claim 1, characterized in that: the electromagnet support 4, the support column 5, the rotation mechanism 6 and other component mechanisms can be adjusted in height according to the actual installation height requirements. 5. The ultra-high-precision force sensor according to claim 1, characterized in that: the shape of the bottom plate 8 can be adjusted as required. 6. The ultra-high precision force sensor according to claim 1, characterized in that: the electromagnet 3 can be an electromagnet of any other shape.

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