Torque measurement system and method and readable storage medium

Abstract

The invention provides a torque measuring system and method and a readable storage medium, and the system comprises a torque measuring device which is used for being connected with a first elastic element of a flexible joint of a robot, and the device comprises a first inductance type position sensor, a second inductance type position sensor and a data processing unit which is connected with the two sensors; the first inductance type position sensor can measure a first rotation angle of an input shaft of the first elastic element and transmit the first rotation angle to the data processing unit; the second inductance type position sensor can measure a second rotation angle of the output shaft of the first elastic element and transmit the second rotation angle to the data processing unit; and the data processing unit obtains the measurement torque of the flexible joint of the robot according to the first rotation angle, the second rotation angle and a pre-obtained rigidity coefficient of the first elastic element. The inductance type position sensor is small in size and low in cost, does not depend on a light source or a permanent magnet to work, and is higher in measurement resolution and precision.

Description

Technical Field

[0001] The present invention relates to the field of robotics, and in particular to a torque measurement system, method and readable storage medium. Background Art

[0002] In order to make the robot joint show passive compliance, an elastic or damping element is added between the drive device and the end effector to replace the rigid and body drive of the traditional robot. This type of robot joint is called a robot SEA (Series Elastic Actuator) joint. Since the elastic element is connected in series, according to Hooke's law, the torque value can be calculated by measuring the torsion angle on both sides of the element and combining it with the calibrated element stiffness coefficient K. Therefore, for the torque measurement of this type of robot joint, the direct force measurement can be converted into position sensing measurement, and the use of dual position sensor solutions to achieve the measurement of torsion angle and torque of robot joints is a current research hotspot.

[0003] However, current robot SEA joint torque measurement methods generally rely on external photoelectric sensors or magnetic sensors for torque measurement, which makes it difficult to simultaneously meet the requirements of miniaturization and high precision during system integration. Therefore, how to achieve a balance between compact design and high-precision measurement has become one of the technical problems that technicians in this field need to solve. Summary of the invention

[0004] The object of the present invention is to provide a torque measurement system, method and readable storage medium to solve one or more problems existing in the prior art, namely, that the torque measurement of robot SEA joints relies on external photoelectric sensors or magnetic sensors, which makes it difficult to simultaneously meet the requirements of miniaturization and high precision during system integration.

[0005] To achieve the above-mentioned object, the present invention is implemented through the following technical solutions: a torque measurement system for measuring the torque of a robot flexible joint, the robot flexible joint comprising a first elastic element, a driving assembly connected to the input shaft of the first elastic element, and an end effector connected to the output shaft of the first elastic element, the torque measurement system comprising a torque measurement device for connecting to the first elastic element, the torque measurement device comprising a first inductive position sensor, a second inductive position sensor and a data processing unit connected to both the first inductive position sensor and the second inductive position sensor, wherein: the first inductive position sensor is used to be connected to the input shaft of the first elastic element, and is configured to: measure a first rotation angle of the input shaft of the first elastic element, and transmit the first rotation angle to the data processing unit; the second inductive position sensor is used to be connected to the output shaft of the first elastic element, and is configured to: measure a second rotation angle of the output shaft of the first elastic element, and transmit the second rotation angle to the data processing unit; the data processing unit is configured to: obtain the measured torque of the robot flexible joint according to the first rotation angle, the second rotation angle and the pre-acquired stiffness coefficient of the first elastic element.

[0006] Optionally, the first inductive position sensor includes a first rotor plate fixedly connected to the input shaft of the first elastic element and a first stator plate fixed on the housing of the robot flexible joint and not in contact with the input shaft of the first elastic element; the second inductive position sensor includes a second rotor plate fixedly connected to the output shaft of the first elastic element and a second stator plate fixed on the housing of the robot flexible joint and not in contact with the output shaft of the first elastic element; a preset spacing is provided between the first rotor plate and the first stator plate, and between the second rotor plate and the second stator plate, and the first stator plate and the second stator plate are both connected to the data processing unit; the first inductive position sensor is configured to: when the first rotor plate rotates, obtain the first rotation angle, and allow the first rotation angle to be transmitted to the data processing unit; the second inductive position sensor is configured to: when the second rotor plate rotates, obtain the second rotation angle, and allow the second rotation angle to be transmitted to the data processing unit.

[0007] Optionally, the first stator plate and the second stator plate are both connected to the data processing unit via a communication interface, and the communication interface includes an RS485 interface or an SPI interface or an I 2 C interface or PWM interface.

[0008] Optionally, the value of the preset spacing is greater than zero and not greater than 1.5 mm.

[0009] Optionally, the torque measurement system further includes a verification device for verifying whether a measurement result of the torque measurement device is accurate.

[0010] Optionally, the verification device includes a power supply unit, a support unit, a power unit installed on the support unit, a torque load unit, a reference torque detection unit and a second elastic element, the torque measuring device is connected to the second elastic element, and the torque measuring device is used to measure the measured torque output by the power unit; the power supply unit is connected to the power unit, the torque load unit and the reference torque detection unit; the driving end of the power unit is connected to the input shaft of the second elastic element through a first connecting component, and the power unit is configured to: drive the first connecting component to rotate to drive the input shaft of the second elastic element to rotate; the torque load unit is connected to the output shaft of the second elastic element through a second connecting component, and the torque load unit is used to add a torque load to the power unit; the reference torque detection unit is connected to the data processing unit, and the reference torque detection unit is configured to: detect the reference torque of the power unit and transmit the reference torque to the data processing unit; the data processing unit is also configured to: verify whether the measurement result of the torque measurement device is accurate based on a preset torque deviation range, the reference torque and the measured torque output by the power unit.

[0011] Optionally, the reference torque detection unit includes a first reference torque detection element connected to the first connection component and a second reference torque detection element connected to the second connection component; the first reference torque detection element is configured to detect a first torque output by the power unit received on the first connection component; the second reference torque detection element is configured to detect a second torque output by the power unit received on the second connection component; the first connection component includes a first coupling, a second coupling, a first transmission shaft and a second transmission shaft, one end of the first coupling is connected to the driving end, the other end of the first coupling is connected to the first reference torque detection element through the first transmission shaft, and the first reference torque detection element is far away from the driving end. One side of the first transmission shaft is connected to one end of the second coupling through the second transmission shaft, and the other end of the second coupling is connected to the input shaft of the second elastic element; the second connecting assembly includes a third coupling, a fourth coupling, a third transmission shaft and a fourth transmission shaft, one end of the third coupling is connected to the torque load unit, the other end of the third coupling is connected to the second reference torque detection element through the third transmission shaft, the side of the second reference torque detection element away from the third transmission shaft is connected to one end of the fourth coupling through the fourth transmission shaft, and the other end of the fourth coupling is connected to the output shaft of the second elastic element; the data processing unit is also configured to obtain the reference torque according to the first torque and the second torque.

[0012] To achieve the above object, the present invention further provides a torque measurement method, using any of the above-mentioned torque measurement systems to measure the measured torque of a flexible joint of a robot, the torque measurement method comprising:

[0013] Acquire a first rotation angle of an input shaft of a first elastic element of the robot flexible joint and a second rotation angle of an output shaft of the first elastic element;

[0014] Obtaining a stiffness coefficient of the first elastic element;

[0015] The measured torque of the flexible joint of the robot is obtained according to the first rotation angle, the second rotation angle and the stiffness coefficient of the first elastic element.

[0016] Optionally, the torque measurement method further includes: verifying whether the measurement result of the torque measurement device is accurate.

[0017] To achieve the above object, the present invention further provides a readable storage medium, wherein the readable storage medium stores a computer program, and when the computer program is executed by a processor, any of the torque measurement methods described above is implemented.

[0018] Compared with the prior art, the torque measurement system, method and readable storage medium provided by the present invention have the following beneficial effects:

[0019] The torque measurement system provided by the present invention is provided with a torque measurement device connected to the first elastic element of the robot flexible joint. The first inductive position sensor in the torque measurement device can measure the first rotation angle of the input shaft of the first elastic element, and the second inductive position sensor in the torque measurement device can measure the second rotation angle of the output shaft of the first elastic element. Then, by connecting both the first inductive position sensor and the second inductive position sensor to a data processing unit, the first rotation angle and the second rotation angle can be transmitted to the data processing unit, providing data support for obtaining the measured torque of the robot flexible joint. Furthermore, by processing the received first rotation angle and the second rotation angle and the pre-acquired stiffness coefficient of the first elastic element through the data processing unit, the measured torque of the robot flexible joint can be obtained. The torque measurement system provided by the present invention measures torque through a torque measurement device. Compared with the device for torque measurement using a photoelectric sensor in the prior art, the first inductive position sensor and the second inductive position sensor used in the present invention are smaller in size, lower in cost, do not need to rely on a light source, and have good anti-environmental interference capabilities; compared with the device for torque measurement using a magnetic sensor in the prior art, it does not need to rely on a permanent magnet, and has higher measurement resolution and accuracy. The torque measurement system provided by the present invention can simultaneously meet the requirements of miniaturization and high precision.

[0020] Furthermore, the torque measurement system further includes a verification device for verifying whether the measurement result of the torque measurement device is accurate. Thus, the torque measurement system provided by the present invention can verify the measurement result of the torque measurement device through the verification device, thereby ensuring the accuracy of the measurement result obtained by the torque measurement device.

[0021] Since the torque measurement method provided by the present invention and the readable storage medium provided by the present invention belong to the same inventive concept as the torque measurement system provided by the present invention, the torque measurement method provided by the present invention and the readable storage medium provided by the present invention at least have all the advantages of the torque measurement system provided by the present invention. For the advantages of the torque measurement method provided by the present invention and the readable storage medium provided by the present invention, please refer to the relevant description of the beneficial effects of the torque measurement system provided by the present invention, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A specific example diagram of a torque measurement system provided in Embodiment 1 of the present invention installed on a flexible joint of a robot;

[0023] Figure 2 for Figure 1 A specific example diagram of the first elastic element in FIG.

[0024] Figure 3 for Figure 1 A specific example diagram of a torque measuring device connected to a first elastic element;

[0025] Figure 4 A specific example diagram of a verification device provided in Embodiment 1 of the present invention;

[0026] Figure 5 A schematic diagram of a structure in which a power unit, a torque load unit, a first reference torque detection element, a second reference torque detection element, and a second elastic element provided in Embodiment 1 of the present invention are installed on a support unit;

[0027] Figure 6 A comparison diagram of a measured torque value measured by a torque measuring device and a reference torque value measured by a torque sensor provided in Embodiment 1 of the present invention;

[0028] Figure 7 A distribution diagram of torque values ​​measured by the torque measuring device provided in this embodiment in a static state;

[0029] Figure 8 A schematic diagram of the overall steps of a torque measurement method provided in Embodiment 2 of the present invention;

[0030] The following are the descriptions of the reference numerals:

[0031] 10-driving motor, 11-first elastic element, 111-inner ring, 112-outer ring, 113-elastic ribs, 114-input shaft of the first elastic element, 115-flange, 116-output shaft of the first elastic element, 12-end effector, 20-torque measuring device, 201-first inductive position sensor, 2011-first rotor plate, 2012-first stator plate, 2013-first fixing ring, 202-second inductive position sensor, 2021-second rotor plate, 2022-second stator plate, 2023-second fixing ring, 30-verification device, 301-support unit, 3011-base, 3012-first support assembly, 3013-second support assembly, 3014-third support assembly , 3015-the fourth supporting assembly, 3016-the fifth supporting assembly, 302-the power unit, 3021-the driving end, 303-the torque load unit, 304-the reference torque detection unit, 3041-the first reference torque detection element, 3042-the second reference torque detection element, 305-the second elastic element, 3051-the input shaft of the second elastic element, 3052-the output shaft of the second elastic element, 306-the first connecting assembly, 3061-the first coupling, 3062-the second coupling, 3063-the first transmission shaft, 3064-the second transmission shaft, 307-the second connecting assembly, 3071-the third coupling, 3072-the fourth coupling, 3073-the third transmission shaft, 3074-the fourth transmission shaft. DETAILED DESCRIPTION

[0032] The torque measurement system, method and readable storage medium proposed in the present invention are further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be more clear. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the drawings. It should be noted that the structure, proportion, size, etc. illustrated in the drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Any modification of the structure, change of the proportional relationship or adjustment of the size, under the same or similar conditions as the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. The specific design features of the present invention disclosed herein include, for example, specific dimensions, directions, positions and shapes, which will be determined in part by the specific environment to be applied and used. And, in the embodiments described below, sometimes the same figure mark is used in different drawings to represent the same part or part with the same function, and its repeated description is omitted.

[0033] Embodiment 1

[0034] This embodiment provides a torque measurement system. Specifically, see Figure 1 , Figure 1 A specific example diagram of a torque measurement system provided in this embodiment installed on a flexible joint of a robot, from Figure 1 It can be seen that the torque measurement system includes a torque measuring device 20 for connecting to the first elastic element 11 of the robot flexible joint, the driving component of the robot flexible joint (including but not limited to the driving motor 10) is connected to the input shaft 114 of the first elastic element, and the output shaft 116 of the first elastic element is connected to the end effector 12; the torque measuring device 20 includes a first inductive position sensor 201 / a second inductive position sensor 202 for connecting to the input shaft 114 of the first elastic element / the output shaft 116 of the first elastic element and a first inductive position sensor 201 and a second inductive position sensor 202. The sensors 202 are all connected to a data processing unit (not shown in the figure); the first inductive position sensor 201 is configured to: measure the first rotation angle of the input shaft 114 of the first elastic element, and transmit the first rotation angle to the data processing unit; the second inductive position sensor 202 is configured to: measure the second rotation angle of the output shaft 116 of the first elastic element, and transmit the second rotation angle to the data processing unit; the data processing unit is configured to: obtain the measured torque of the robot flexible joint according to the first rotation angle, the second rotation angle and the pre-acquired stiffness coefficient of the first elastic element 11.

[0035] Therefore, the torque measurement system provided in this embodiment is provided with a torque measurement device 20 connected to the first elastic element 11 of the robot flexible joint. The first inductive position sensor 201 in the torque measurement device 20 can measure the first rotation angle of the input shaft 114 of the first elastic element, and the second inductive position sensor 202 in the torque measurement device 20 can measure the second rotation angle of the output shaft 116 of the first elastic element. Then, by connecting the first inductive position sensor 201 and the second inductive position sensor 202 to the data processing unit, the first rotation angle and the second rotation angle can be transmitted to the data processing unit, providing data support for obtaining the measured torque of the robot flexible joint. Furthermore, by processing the received first rotation angle and the second rotation angle and the pre-acquired stiffness coefficient of the first elastic element 11 through the data processing unit, the measured torque of the robot flexible joint can be obtained. The torque measurement system provided in the present embodiment measures torque through a torque measurement device 20. Compared with the device for torque measurement using a photoelectric sensor in the prior art, the first inductive position sensor 201 and the second inductive position sensor 202 used in the present embodiment are smaller in size, lower in cost, do not need to rely on a light source, and have good anti-environmental interference capabilities; compared with the device for torque measurement using a magnetic sensor in the prior art, it does not need to rely on a permanent magnet, and has higher measurement resolution and accuracy. The torque measurement system provided in the present embodiment can meet the requirements of miniaturization and high precision at the same time.

[0036] For details, please refer to Figure 1 ,from Figure 1 It can be seen that, for the first inductive position sensor 201, the first inductive position sensor 201 is used to be connected to the input shaft 114 of the first elastic element; for the second inductive position sensor 202, the second inductive position sensor 202 is used to be connected to the output shaft 116 of the first elastic element.

[0037] It should be noted that, as those skilled in the art can understand, the drive assembly includes a driver (not shown in the figure) and a drive motor 10 connected to the driver, the drive shaft of the drive motor 10 is connected to the input shaft 114 of the first elastic element, and the driver can supply power to the drive motor 10.

[0038] For example, see Figure 2 , Figure 2 for Figure 1 A specific example of the first elastic element 11 in FIG. Figure 2It can be seen that in some exemplary embodiments, the first elastic element 11 includes an inner ring 111 and an outer ring 112, the inner ring 111 and the outer ring 112 are connected by elastic ribs 113, the inner ring 111 is connected to the input shaft 114 of the first elastic element, and the outer ring 112 is connected to the output shaft 116 of the first elastic element via a flange 115.

[0039] Preferably, see Figure 3 , Figure 3 for Figure 1 A specific example diagram of the connection between the torque measuring device 20 and the first elastic element 11. Figure 3 It can be seen that in some exemplary embodiments, the first inductive position sensor 201 includes a first rotor plate 2011 for fixedly connected to the input shaft 114 of the first elastic element and a first stator plate 2012 for being fixed on the housing of the robot flexible joint (not shown in the figure) and not in contact with the input shaft 114 of the first elastic element, a preset distance is provided between the first rotor plate 2011 and the first stator plate 2012, and the first stator plate 2012 is connected to the data processing unit; the first inductive position sensor 201 is configured to: when the first rotor plate 2011 rotates, obtain the first rotation angle, and transmit the first rotation angle to the data processing unit. Therefore, the first rotor plate 2011 is fixedly connected to the input shaft 114 of the first elastic element, so that when the driving motor 10 drives the input shaft 114 of the first elastic element to rotate, the first rotor plate 2011 can be driven to rotate, and the rotation of the first rotor plate 2011 can generate eddy currents, resulting in changes in the spatial magnetic field, so that the first stator plate 2012 generates an induced voltage signal related to the first rotation angle, and the inductor chip on the first stator plate 2012 can collect, process and transmit the induced voltage signal. The induced voltage signal is transmitted to the data processing unit for collection and protocol analysis, and then the first rotation angle can be obtained.

[0040] Specifically, the first rotor plate 2011 and the first stator plate 2012 are both in the shape of a ring. The first rotor plate 2011 is fixed on the first fixing ring 2013, and then is fixed on the input shaft 114 of the first elastic element through the first fixing ring 2013; the first stator plate 2012 is fixed to the outer shell of the robot flexible joint through a first fixing mold (not shown in the figure), so that the first stator plate 2012 can be mounted on the input shaft 114 of the first elastic element and has no contact with the input shaft.

[0041] For further information, please see Figure 3 ,from Figure 3It can be seen that in some exemplary embodiments, the second inductive position sensor 202 includes a second rotor plate 2021 for fixedly connected to the output shaft 116 of the first elastic element and a second stator plate 2022 for being fixed on the housing of the robot flexible joint and not in contact with the output shaft 116 of the first elastic element, a preset distance is provided between the second rotor plate 2021 and the second stator plate 2022, and the second stator plate 2022 is connected to the data processing unit; the second inductive position sensor 202 is configured to: when the second rotor plate 2021 rotates, obtain the second rotation angle, and transmit the second rotation angle to the data processing unit. Therefore, the second rotor plate 2021 is fixedly connected to the output shaft 116 of the first elastic element, so that when the drive motor 10 drives the input shaft 114 of the first elastic element to rotate and drives the output shaft 116 of the first elastic element to rotate, it can drive the second rotor plate 2021 to rotate. The rotation of the second rotor plate 2021 can generate eddy currents, resulting in changes in the spatial magnetic field, so that the second stator plate 2022 generates an induced voltage signal related to the second rotation angle. The inductor chip on the second stator plate 2022 can collect, process and transmit the induced voltage signal. The induced voltage signal is transmitted to the data processing unit for collection and protocol analysis, and then the second rotation angle can be obtained.

[0042] Specifically, the second rotor plate 2021 and the second stator plate 2022 are both in the shape of a circular ring. The second rotor plate 2021 is fixed on the second fixing ring 2023, and then is fixed on the output shaft 116 of the first elastic element through the second fixing ring 2023; the second stator plate 2022 is fixed to the outer shell of the robot flexible joint through a second fixing mold (not shown in the figure), so that the second stator plate 2022 can be mounted on the output shaft 116 of the first elastic element and has no contact with the output shaft.

[0043] It should be noted that the first rotor plate 2011, the second rotor plate 2021, the first stator plate 2012 and the second stator plate 2022 in the present invention are all printed circuit boards, so that the first inductive position sensor 201 and the second inductive position sensor 202 have a smaller volume.

[0044] It should be noted that, in some exemplary embodiments, the first stator plate 2012 in the first inductive position sensor 201 and the second stator plate 2022 in the second inductive position sensor 202 are both connected to the driver in the driving assembly, and the first inductive position sensor 201 and the second inductive position sensor 202 are powered by the driver.

[0045] Preferably, the first stator plate 2012 / the second stator plate 2022 is connected to the data processing unit via a communication interface (not shown in the figure), and the communication interface includes an RS485 interface or an SPI interface or an I 2 C interface or PWM interface. Thus, the first stator plate 2012 and the second stator plate 2022 are connected via RS485 interface or SPI interface or I 2 The C interface or PWM interface is connected to the data processing unit, which can provide stable and long-distance data transmission and has strong anti-interference ability.

[0046] Specifically, the first stator plate 2012 and the second stator plate 2022 are both provided with a communication interface, and the first stator plate 2012 and the second stator plate 2022 are both connected to the data processing unit through the communication interface.

[0047] Exemplarily, in some exemplary embodiments, the value of the preset spacing is greater than zero and not greater than 1.5 mm.

[0048] It should be noted that the above is merely an exemplary description of the value range of the preset interval, and is not a limitation of the present invention.

[0049] It should be noted that, as those skilled in the art can understand, the present invention does not impose too many restrictions on the type of the data processing unit and the method for obtaining the stiffness coefficient of the first elastic element 11. For example, in some exemplary embodiments, the data processing unit may be a host computer, and the stiffness coefficient of the first elastic element 11 may be obtained by a static method.

[0050] In order to facilitate understanding of the present invention, the process of using the data processing unit to obtain the measured torque of the flexible joint of the robot is described as an example.

[0051] First, the data processing unit obtains the angle value of the first rotation angle of the input shaft 114 of the first elastic element, the rotation direction of the input shaft 114 of the first elastic element, and the angle value of the second rotation angle of the output shaft 116 of the first elastic element. Then, the angle value of the second rotation angle is subtracted from the angle value of the first rotation angle, and the obtained difference is multiplied by the pre-acquired stiffness coefficient of the first elastic element 11 to obtain a product. Finally, according to the product and the rotation direction of the input shaft 114 of the first elastic element, the torque value and torque direction of the measured torque of the robot flexible joint can be obtained; specifically, the absolute value of the product is used as the torque value of the measured torque of the robot flexible joint. If the product is a positive number, the torque direction of the measured torque of the robot flexible joint is the same as the rotation direction of the input shaft 114 of the first elastic element. If the product is a negative number, the torque direction of the measured torque of the robot flexible joint is opposite to the rotation direction of the input shaft 114 of the first elastic element. If the product is zero, the torque value of the measured torque of the robot flexible joint is zero, and the robot flexible joint does not twist.

[0052] It should be noted that the above is merely an exemplary description of the process of using the data processing unit to obtain the measured torque of the flexible joint of the robot, and is not a limitation of the present invention.

[0053] Exemplarily, in some other embodiments, when obtaining the difference between the angle value of the first rotation angle and the angle value of the second rotation angle, the angle value of the second rotation angle minus the angle value of the first rotation angle can also be used. In this case, the obtained difference is still multiplied by the stiffness coefficient of the first elastic element 11 obtained in advance to obtain the product, and the absolute value of the product is used as the torque value of the measured torque of the robot flexible joint; however, if the product is a positive number, the torque direction of the measured torque of the robot flexible joint is opposite to the rotation direction of the input shaft 114 of the first elastic element; if the product is a negative number, the torque direction of the measured torque of the robot flexible joint is the same as the rotation direction of the input shaft 114 of the first elastic element.

[0054] Furthermore, the torque measurement system further includes a verification device 30 for verifying whether the measurement result of the torque measurement device 20 is accurate. Thus, the measurement result of the torque measurement device 20 can be verified by the verification device 30, thereby ensuring the accuracy of the measurement result obtained by the torque measurement device 20.

[0055] For example, see Figure 4 , Figure 4 FIG. 1 is a specific example diagram of the verification device 30 provided in this embodiment. Figure 4It can be seen that in some exemplary embodiments, the verification device 30 includes a power supply unit (not shown in the figure), a support unit 301, and a power unit 302, a torque load unit 303, a reference torque detection unit 304, and a second elastic element 305 installed on the support unit 301. The torque measuring device 20 is connected to the second elastic element 305, and the torque measuring device 20 is used to measure the measured torque output by the power unit 302; the power supply unit is connected to the power unit 302, the torque load unit 303, and the reference torque detection unit 304; the driving end 3021 of the power unit 302 is connected to the input shaft 3051 of the second elastic element through the first connecting component 306, and the power unit 302 is configured The first connection component 306 is driven to rotate so as to drive the input shaft 3051 of the second elastic element to rotate; the torque load unit 303 is connected to the output shaft 3052 of the second elastic element through the second connection component 307, and the torque load unit 303 is used to add a torque load to the power unit 302; the reference torque detection unit 304 is connected to the data processing unit, and the reference torque detection unit 304 is configured to: detect the reference torque of the power unit 302 and transmit the reference torque to the data processing unit; the data processing unit is also configured to: verify whether the measurement result of the torque measurement device 20 is accurate according to the preset torque deviation range, the reference torque and the measured torque output by the power unit 302.

[0056] It should be noted that the present invention does not impose too many restrictions on the specific setting interval of the preset torque deviation range. If the deviation value between the measured torque output by the power unit 302 measured by the torque measuring device 20 and the reference torque measured by the reference torque detection unit 304 is within the preset torque deviation range, the measurement result of the torque measuring device 20 is accurate; if the deviation value between the measured torque output by the power unit 302 measured by the torque measuring device 20 and the reference torque measured by the reference torque detection unit 304 is not within the preset torque deviation range, the measurement result of the torque measuring device 20 is inaccurate.

[0057] For example, please see Figure 4 and Figure 5 ,in, Figure 5 The schematic diagram of the structure of the power unit 302, the torque load unit 303, the first reference torque detection element 3041, the second reference torque detection element 3042 and the second elastic element 305 provided in this embodiment are installed on the support unit 301. Figure 4 and Figure 5It can be seen that in some exemplary embodiments, the reference torque detection unit 304 includes a first reference torque detection element 3041 connected to the first connection component 306 and a second reference torque detection element 3042 connected to the second connection component 307; the first reference torque detection element 3041 is configured to: detect the first torque output by the power unit 302 received on the first connection component 306; the second reference torque detection element 3042 is configured to: detect the second torque output by the power unit 302 received on the second connection component 307; the first connection component 306 includes a first coupling 3061, a second coupling 3062, a first transmission shaft 3063 and a second transmission shaft 3064, one end of the first coupling 3061 is connected to the driving end 3021, the other end of the first coupling 3061 is connected to the first reference torque detection element 3041 through the first transmission shaft 3063, and the first reference torque detection element 30 41, a side away from the first transmission shaft 3063 is connected to one end of the second coupling 3062 through the second transmission shaft 3064, and the other end of the second coupling 3062 is connected to the input shaft 3051 of the second elastic element; the second connecting assembly 307 includes a third coupling 3071, a fourth coupling 3072, a third transmission shaft 3073 and a fourth transmission shaft 3074, one end of the third coupling 3071 is connected to the torque load unit 303, the other end of the third coupling 3071 is connected to the second reference torque detection element 3042 through the third transmission shaft 3073, the side of the second reference torque detection element 3042 away from the third transmission shaft 3073 is connected to one end of the fourth coupling 3072 through the fourth transmission shaft 3074, and the other end of the fourth coupling 3072 is connected to the output shaft 3052 of the second elastic element; the data processing unit is also configured to: obtain the reference torque according to the first torque and the second torque.

[0058] It should be noted that in the present invention, the average value of the first torque and the second torque can be obtained by the data processing unit and the average value can be used as the reference torque, thereby improving the accuracy of the reference torque obtained and thus improving the reliability of the verification device 30.

[0059] For example, please see Figure 5 ,from Figure 5It can be seen that in some exemplary embodiments, the support unit 301 includes a base 3011, on which is fixedly connected a first support assembly 3012 for mounting the power unit 302, a second support assembly 3013 for mounting the torque load unit 303, a third support assembly 3014 for mounting the first reference torque detection element 3041, a fourth support assembly 3015 for mounting the second reference torque detection element 3042, and a fifth support assembly 3016 for mounting the second elastic element 305.

[0060] Preferably, the power unit 302 includes a robot joint, through which torque is output; the torque load unit 303 includes a magnetic powder brake, through which a torque load is added, thereby simulating an external load; the reference torque detection unit 304 includes a torque sensor, through which the actual torque can be directly measured.

[0061] Preferably, the structure of the second elastic element 305 is the same as that of the first elastic element 11 , and the torque range of the second elastic element 305 includes 0-20 Nm.

[0062] In order to better understand the present invention, please continue to refer to Figures 1 to 5 as well as Figure 6 and Figure 7 ,in, Figure 6 A comparison diagram of the measured torque value measured by the torque measuring device 20 provided in this embodiment and the reference torque value measured by the torque sensor; Figure 7 The torque value distribution diagram of the torque measuring device 20 provided in this embodiment measured in a static state, that is, the torque output by the power unit 302 is zero; Figure 6 and Figure 7 The horizontal axes in the figure all represent data points, and the vertical axes all represent torque values. The following is an exemplary description of the method for using the torque measurement system provided by the present invention.

[0063] First, the first inductive position sensor 201 and the second inductive position sensor 202 in the torque measuring device 20 are respectively installed on the input shaft and the output shaft of the elastic element of the flexible joint of the robot to be measured, and the rotation angle of the two ends of the elastic element is measured, and the data is transmitted to the host computer through the RS485 communication protocol. The host computer obtains the measured torque of the flexible joint of the robot to be measured based on the data and the pre-acquired stiffness coefficient of the elastic element of the flexible joint of the robot to be measured.

[0064] Then, in order to ensure the correctness of the measured torque of the flexible joint of the robot to be measured, the verification device 30 is used to verify whether the measurement result of the torque measuring device 20 is accurate. Specifically, an elastic element that is the same as the elastic element of the flexible joint of the robot to be measured is used, and the torque measuring device 20 is connected to the elastic element. Torque is output through the robot joint, the rotation speed of the power end of the robot joint is 100rpm, and a magnetic powder brake is used to add a torque load; the rotation angle of the two ends of the elastic element is measured by the torque measuring device 20, and the actual torque is measured by two torque sensors. The two rotation angles and two actual torques are transmitted to the host computer, and the measured torque value ( Figure 6 The red line in the figure) is compared with the reference torque value measured by the torque sensor ( Figure 6 The blue line in the figure shows the comparison chart. Figure 6 It can be seen that in low-speed application scenarios, the torque measurement accuracy of the torque measuring device 20 is approximately 0.1 Nm.

[0065] In addition, the host computer can also obtain the torque value distribution diagram measured by the torque measuring device 20 in a static state, Figure 7 It can be seen that the torque measurement resolution of the torque measuring device 20 is approximately ±0.01 Nm.

[0066] Embodiment 2

[0067] This embodiment provides a torque measurement method, which uses the torque measurement system described in any of the above embodiments to measure the measured torque of the flexible joint of the robot. Figure 8 , Figure 8 The overall steps of the torque measurement method provided in this embodiment are shown in FIG. Figure 8 It can be seen that the torque measurement method includes:

[0068] S100: Acquire a first rotation angle of an input shaft 114 of a first elastic element of the robot flexible joint and a second rotation angle of an output shaft 116 of the first elastic element;

[0069] S200: Obtaining a stiffness coefficient of the first elastic element 11;

[0070] S300 : Acquire the measured torque of the robot flexible joint according to the first rotation angle, the second rotation angle, and the stiffness coefficient of the first elastic element 11 .

[0071] It should be noted that the present invention does not impose too many restrictions on the execution order of step S100 and step S200. For example, in some embodiments, step S100 may be executed first, and then step S200; in other embodiments, step S200 may be executed first, and then step S100; in still other embodiments, step S100 and step S200 may be executed simultaneously.

[0072] Since the torque measurement method provided in this embodiment and the torque measurement system described in any of the above-mentioned embodiments belong to the same inventive concept, the torque measurement method provided in this embodiment has at least all the advantages of the torque measurement systems provided in the above-mentioned embodiments. For the advantages of the torque measurement method provided in this embodiment, please refer to the relevant description of the beneficial effects of the torque measurement systems provided in the above-mentioned embodiments, which will not be repeated here.

[0073] Preferably, the torque measurement method further comprises: verifying whether the measurement result of the torque measurement device 20 is accurate. Thus, the reliability of the torque measurement device 20 can be improved.

[0074] Embodiment 3

[0075] This embodiment provides a readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the torque measurement method described in any of the above embodiments is implemented.

[0076] Since the readable storage medium provided in this embodiment and the torque measurement method described in any of the above embodiments belong to the same inventive concept, the readable storage medium provided in this embodiment has at least all the advantages of the torque measurement method provided in the above embodiments. For the advantages of the readable storage medium provided in this embodiment, please refer to the relevant description of the beneficial effects of the torque measurement method provided in the above embodiments, which will not be repeated here.

[0077] In summary, the torque measurement system, method and readable storage medium provided by the present invention have the following advantages: the torque measurement system provided by the present invention, by setting a torque measurement device connected to the first elastic element of the robot flexible joint, the first inductive position sensor in the torque measurement device can measure the first rotation angle of the input shaft of the first elastic element, and the second inductive position sensor in the torque measurement device can measure the second rotation angle of the output shaft of the first elastic element. Then, by connecting the first inductive position sensor and the second inductive position sensor to the data processing unit, the first rotation angle and the second rotation angle can be transmitted to the data processing unit, providing data support for obtaining the measured torque of the robot flexible joint. Furthermore, by processing the received first rotation angle and the second rotation angle and the pre-acquired stiffness coefficient of the first elastic element through the data processing unit, the measured torque of the robot flexible joint can be obtained. The torque measurement system provided by the present invention measures torque through a torque measurement device. Compared with the device for torque measurement using a photoelectric sensor in the prior art, the first inductive position sensor and the second inductive position sensor used in the present invention are smaller in size, lower in cost, do not need to rely on a light source, and have good anti-environmental interference capabilities; compared with the device for torque measurement using a magnetic sensor in the prior art, it does not need to rely on a permanent magnet, and has higher measurement resolution and accuracy. The torque measurement system provided by the present invention can simultaneously meet the requirements of miniaturization and high precision.

[0078] Furthermore, the torque measurement system further includes a verification device for verifying whether the measurement result of the torque measurement device is accurate. Thus, the torque measurement system provided by the present invention can verify the measurement result of the torque measurement device through the verification device, thereby ensuring the accuracy of the measurement result obtained by the torque measurement device.

[0079] Since the torque measurement method provided by the present invention and the readable storage medium provided by the present invention belong to the same inventive concept as the torque measurement system provided by the present invention, the torque measurement method provided by the present invention and the readable storage medium provided by the present invention at least have all the advantages of the torque measurement system provided by the present invention. For the advantages of the torque measurement method provided by the present invention and the readable storage medium provided by the present invention, please refer to the relevant description of the beneficial effects of the torque measurement system provided by the present invention, which will not be repeated here.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A torque measurement system for measuring the torque of a flexible joint of a robot, wherein the flexible joint of the robot comprises a first elastic element, a driving assembly connected to an input shaft of the first elastic element, and an end effector connected to an output shaft of the first elastic element, wherein: The torque measurement system comprises a torque measurement device for connecting to the first elastic element, the torque measurement device comprises a first inductive position sensor, a second inductive position sensor and a data processing unit connected to both the first inductive position sensor and the second inductive position sensor, wherein: The first inductive position sensor is used to be connected to the input shaft of the first elastic element, and is configured to: measure a first rotation angle of the input shaft of the first elastic element, and transmit the first rotation angle to the data processing unit; The second inductive position sensor is used to be connected to the output shaft of the first elastic element, and is configured to: measure a second rotation angle of the output shaft of the first elastic element, and transmit the second rotation angle to the data processing unit; The data processing unit is configured to obtain the measured torque of the robot flexible joint according to the first rotation angle, the second rotation angle and the pre-acquired stiffness coefficient of the first elastic element.

2. The torque measurement system according to claim 1, characterized in that: The first inductive position sensor comprises a first rotor plate for fixedly connecting with the input shaft of the first elastic element and a first stator plate for fixing on the housing of the robot flexible joint and not contacting with the input shaft of the first elastic element; the second inductive position sensor comprises a second rotor plate for fixedly connecting with the output shaft of the first elastic element and a second stator plate for fixing on the housing of the robot flexible joint and not contacting with the output shaft of the first elastic element; a preset distance is provided between the first rotor plate and the first stator plate, and between the second rotor plate and the second stator plate, and the first stator plate and the second stator plate are both connected to the data processing unit; The first inductive position sensor is configured to: acquire the first rotation angle when the first rotor plate rotates, and transmit the first rotation angle to the data processing unit; The second inductive position sensor is configured to obtain the second rotation angle when the second rotor plate rotates, and transmit the second rotation angle to the data processing unit.

3. The torque measurement system according to claim 2, characterized in that: The first stator plate and the second stator plate are both connected to the data processing unit via a communication interface, wherein the communication interface includes an RS485 interface, an SPI interface, or an I 2 C interface or PWM interface.

4. The torque measurement system according to claim 2, characterized in that: The value of the preset spacing is greater than zero and not greater than 1.5 mm.

5. The torque measurement system according to claim 1, characterized in that: The torque measurement system further comprises a verification device for verifying whether a measurement result of the torque measurement device is accurate.

6. The torque measurement system according to claim 5, characterized in that: The verification device comprises a power supply unit, a support unit, and a power unit installed on the support unit, a torque load unit, a reference torque detection unit and a second elastic element, the torque measuring device is connected to the second elastic element, and the torque measuring device is used to measure the measured torque output by the power unit; the power supply unit is connected to the power unit, the torque load unit and the reference torque detection unit; The driving end of the power unit is connected to the input shaft of the second elastic element through a first connecting assembly, and the power unit is configured to: drive the first connecting assembly to rotate so as to drive the input shaft of the second elastic element to rotate; The torque load unit is connected to the output shaft of the second elastic element through a second connecting assembly, and the torque load unit is used to add a torque load to the power unit; The reference torque detection unit is connected to the data processing unit, and the reference torque detection unit is configured to: detect the reference torque of the power unit and transmit the reference torque to the data processing unit; The data processing unit is further configured to verify whether the measurement result of the torque measuring device is accurate according to a preset torque deviation range, the reference torque and the measured torque output by the power unit.

7. The torque measurement system according to claim 6, characterized in that: The reference torque detection unit includes a first reference torque detection element connected to the first connection component and a second reference torque detection element connected to the second connection component; The first reference torque detection element is configured to: detect a first torque output by the power unit received by the first connection assembly; The second reference torque detection element is configured to: detect a second torque output by the power unit received by the second connecting assembly; The first connection assembly includes a first coupling, a second coupling, a first transmission shaft and a second transmission shaft, one end of the first coupling is connected to the driving end, the other end of the first coupling is connected to the first reference torque detection element through the first transmission shaft, a side of the first reference torque detection element away from the first transmission shaft is connected to one end of the second coupling through the second transmission shaft, and the other end of the second coupling is connected to the input shaft of the second elastic element; The second connection assembly includes a third coupling, a fourth coupling, a third transmission shaft and a fourth transmission shaft, one end of the third coupling is connected to the torque load unit, the other end of the third coupling is connected to the second reference torque detection element through the third transmission shaft, a side of the second reference torque detection element away from the third transmission shaft is connected to one end of the fourth coupling through the fourth transmission shaft, and the other end of the fourth coupling is connected to the output shaft of the second elastic element; The data processing unit is further configured to obtain the reference torque according to the first torque and the second torque.

8. A torque measurement method, characterized in that: The torque measurement system according to any one of claims 1 to 7 is used to measure the measured torque of the flexible joint of the robot, and the torque measurement method comprises: Acquire a first rotation angle of an input shaft of a first elastic element of the robot flexible joint and a second rotation angle of an output shaft of the first elastic element; Obtaining a stiffness coefficient of the first elastic element; The measured torque of the flexible joint of the robot is obtained according to the first rotation angle, the second rotation angle and the stiffness coefficient of the first elastic element.

9. The torque measurement method according to claim 8, characterized in that: The torque measurement method further includes: verifying whether a measurement result of the torque measurement device is accurate.

10. A readable storage medium, characterized in that: The readable storage medium stores a computer program, and when the computer program is executed by a processor, the torque measurement method according to any one of claims 8 to 9 is implemented.

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