Joint torque sensor and robot

Abstract

The invention provides a joint torque sensor and a robot. The joint torque sensor comprises at least two strain beams and a strain gauge, wherein each strain beam comprises a first mounting surface and a second mounting surface which are oppositely arranged; strain gauges are mounted on each first mounting surface and each second mounting surface; the plane where each first installation face and each second installation face are located intersects with the direction of torque. Wherein the strain gauge comprises at least one strain gauge, the joint torque sensor further comprises a bridge formed by connecting the strain gauges, and a bridge arm of the bridge at least comprises the strain gauges which are correspondingly arranged on a first mounting surface and a second mounting surface on the same strain beam and are arranged in series. The joint torque sensor provided by the invention can improve the detection precision.

Description

Technical Field

[0001] The present application relates to the technical field of sensors, and in particular, to a joint torque sensor and a robot. Background Art

[0002] With the progress of the automation industry, robots are more and more widely used. The joint torque sensor is installed in each joint of the robot to measure torque. However, in the actual use process, the joint torque sensor not only bears the torque of the drive shaft, but also bears the radial torque and force of the drive shaft, etc. The additional torque and force will affect the torque of the drive shaft to be measured, resulting in low detection accuracy of the joint torque sensor. Summary of the Invention

[0003] To solve the above technical problems, the present application provides a joint torque sensor and a robot to improve the technical problem of low detection accuracy of the existing joint torque sensor.

[0004] One technical solution adopted by the present application is: to provide a joint torque sensor, which includes at least two strain beams and strain gauges. Each strain beam includes a first mounting surface and a second mounting surface arranged opposite to each other; a strain gauge, and a strain gauge is installed on each first mounting surface and each second mounting surface; wherein, the planes where each first mounting surface and each second mounting surface are located intersect with the direction of the torque; wherein, the strain gauge includes at least one strain gauge, and the joint torque sensor further includes a bridge formed by connecting the strain gauges. At least one arm of the bridge includes strain gauges corresponding to and serially arranged on the first mounting surface and the second mounting surface of the same strain beam.

[0005] In one embodiment, the number of bridges is the same as the number of strain gauges provided in each strain gauge; each bridge is formed by connecting one of the strain gauges on the first mounting surfaces of all the strain beams and one of the strain gauges on the second mounting surfaces of all the strain beams.

[0006] In one embodiment, along the positive projection direction of the first mounting surface of each strain beam towards the corresponding second mounting surface, the strain gauges on the first mounting surface and the second mounting surface of each strain beam coincide with each other.

[0007] In one embodiment, the bridge includes a first bridge and a second bridge, and each strain gauge includes a first strain gauge and a second strain gauge; wherein, the first strain gauges corresponding to each other on the first mounting surface and the second mounting surface of at least two strain beams are connected to form a first bridge, and the bridge arms of the first bridge at least include the first strain gauges on the first mounting surface and the second mounting surface of the same strain beam; the second strain gauges corresponding to each other on the first mounting surface and the second mounting surface of at least two strain beams are connected to form a second bridge, and the bridge arms of the second bridge at least include the second strain gauges on the first mounting surface and the second mounting surface of the same strain beam; wherein, the first bridge and the second bridge are connected in parallel.

[0008] In one embodiment, the joint torque sensor includes an inner ring part and an outer ring part arranged concentrically, wherein, the inner ring part is located inside the outer ring part; each strain beam is connected to the inner ring part and the outer ring part.

[0009] In one embodiment, the strain beams are evenly distributed around the center of the inner ring part, and two corresponding strain beams are centrosymmetrically arranged with respect to the center of the circle.

[0010] In one embodiment, the first mounting surface and the second mounting surface of each strain beam are oppositely arranged along the axial direction of the inner ring part; two strain gauges are provided on the strain gauges on each first mounting surface and each second mounting surface.

[0011] The present application provides a robot, which includes a joint and the above-mentioned joint torque sensor, and the joint torque sensor is installed at the joint.

[0012] The beneficial effect of the present application is that: the joint torque sensor of the present application includes at least two strain beams and strain gauges, the first mounting surface and the second mounting surface of each strain beam are both installed with strain gauges, and the planes where each first mounting surface and each second mounting surface are located intersect with the direction of the torque. Therefore, the strain gauge on the first mounting surface of the same strain beam detects positive strain, and the strain gauge on the second mounting surface opposite to the first mounting surface can detect negative strain, or when the strain gauge on the first mounting surface of the same strain beam detects negative strain, the strain gauge on the second mounting surface opposite to the first mounting surface can detect positive strain. The positive and negative strains are equal within the error range, so the detection results of the first mounting surface and the second mounting surface can cancel each other out, that is, it can cancel the errors generated by other bending moments and torques on the torque, thereby improving the detection accuracy of the joint torque sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings, where: Figure 1 It is a schematic structural diagram of the first view of an embodiment of the joint torque sensor provided by the present application; Figure 2 is Figure 1 a schematic structural diagram of the second view of the joint torque sensor of the embodiment; Figure 3 It is a schematic circuit diagram of the first embodiment of the bridge provided by the present application; Figure 4 It is a schematic circuit diagram of the second embodiment of the bridge provided by the present application; Figure 5 It is a schematic circuit diagram of the third embodiment of the bridge provided by the present application. Detailed implementation manners

[0014] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0015] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present application, then the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0016] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, then the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0017] The present application provides a joint torque sensor that can be applied to a robot. Among them, the robot includes joints, and the joint torque sensor is arranged on the joints. The joint torque sensor can convert the force applied to the joints into an electrical signal, that is, it can sense and measure the magnitude of the force by measuring the deformation or the change in the output voltage generated after being stressed. Among them, the robot can be a robot that can move as a whole, or the robot can also be a robot that can move partially. For example, the robot that can move partially can be a robotic arm, which is not limited herein.

[0018] Referring to Figures 1 to 2 , Figure 1 FIG. Figure 2 is Figure 1 a schematic structural view of the first view of an embodiment of the joint torque sensor provided by the present application. The present application sets the X-axis, Y-axis, and Z-axis that are orthogonal to each other in the first view of the joint torque sensor as a three-dimensional coordinate system. Among them, the present application takes the drive shaft as the Z-axis, and hereinafter, the Z-axis will be used to describe it; among them, the joint torque sensor of the present application is subjected to a torque along the drive shaft, that is, along the Z-axis, which is the Z-axis torque. The X-axis and the Y-axis are perpendicular to each other, and both the X-axis and the Y-axis are perpendicular to the Z-axis, specifically as shown in Figure 1 . The present application takes improving the detection accuracy of the Z-axis torque of the joint torque sensor of the present application as an example for illustration. Therefore, the torque described in the present application is the Z-axis torque, and hereinafter, the Z-axis torque will be used to describe it; the torque or force received by the X-axis or Y-axis of the joint torque sensor of the present application is other torque or other force.

[0019] The joint torque sensor 10 provided by the present application includes an inner ring portion 110, an outer ring portion 120, at least two strain beams 130, and a strain gauge 140. Among them, the inner ring portion 110 and the outer ring portion 120 are concentrically arranged, and the inner ring portion 110 is located inside the outer ring portion 120. Each strain beam 130 is connected to both the inner ring portion 110 and the outer ring portion 120. The strain gauge 140 is arranged on the strain beam 130. Among them, the inner ring portion 110 is used to connect the drive shaft. After the inner ring portion 110 is applied with the torque around each axis or the force in the direction of each axis, the force is transmitted to the strain beam 130 connected thereto. The strain beam 130 is deformed accordingly, resulting in a change in the resistance parameter of the strain gauge 140 arranged on the strain beam 130. Thus, the Z-axis torque can be calculated through the resistance parameter.

[0020] Among at least two strain beams 130, the strain beams 130 may be asymmetrically distributed along the circumferential direction of the inner ring portion 110. Preferably, the strain beams 130 are evenly distributed along the circumferential direction of the inner ring portion 110 (not marked in the figure). Among them, if the number of strain beams 130 is an even number, two opposite strain beams 130 may be symmetrically arranged. It can be understood that two opposite strain beams 130 among an even number of strain beams 130 are symmetrically arranged, so that the joint torque sensor 10 can ensure the balance of force conduction. For example, as Figure 1 shown, the joint torque sensor 10 includes four strain beams 130, and the included angle between the extension lines of every two adjacent strain beams 130 is 90° cross. Among them, two strain beams 130 are a group and are opposite and symmetrically arranged; the other two strain beams 130 are a group and are opposite and symmetrically arranged; these two groups of strain beams 130 are arranged in a cross.

[0021] Each strain beam 130 includes a first mounting surface 131 and a second mounting surface (not shown in the figure) arranged oppositely. A strain gauge 140 is mounted on each first mounting surface 131 and each second mounting surface. Among them, the plane where each first mounting surface 131 and each second mounting surface are located intersects with the Z-axis torque direction, and the Z-axis torque direction is parallel to the Z-axis. That is to say, as long as there is an included angle between each first mounting surface 131 and each second mounting surface and the Z-axis, it is not necessary to be parallel. Preferably, as Figure 1 shown, each first mounting surface 131 and each second mounting surface are perpendicular to the Z-axis, that is, perpendicular to the Z-axis torque intersection.

[0022] Since strain gauges 140 are mounted on both the first mounting surface 131 and the second mounting surface of each strain beam 130 of the present application, and the plane where each first mounting surface 131 and each second mounting surface are located intersects with the direction of the Z-axis torque. Therefore, when the joint torque sensor 10 bears additional forces and torques, the strain gauge 140 on the first mounting surface 131 of the same strain beam 130 detects positive strain, and the strain gauge 140 on the second mounting surface opposite to the first mounting surface can detect negative strain; or when the strain gauge 140 on the first mounting surface 131 of the same strain beam 130 detects negative strain, the strain gauge 140 on the second mounting surface opposite to the first mounting surface can detect positive strain. The positive and negative strains are equal within the error range, so the detection results of the first mounting surface 131 and the second mounting surface can cancel each other out, that is, the errors generated by other bending moments and torques on the Z-axis torque can be cancelled, thereby improving the detection accuracy of the joint torque sensor 10. In addition, when the same strain beam 130 of the present application is stressed, the oppositely arranged first mounting surface 131 and second mounting surface will undergo different deformations, so the strain gauges 140 generate opposite signals. Therefore, the requirements for the position and angle of the strain gauges 140 in the present application are low, and the joint torque sensor 10 of the present application is simpler to manufacture.

[0023] In one embodiment, in order to improve the detection accuracy of the joint torque sensor 10, each strain beam 130 further includes a third mounting surface 133 and a fourth mounting surface which are oppositely arranged, wherein the third mounting surface 133 and the fourth mounting surface are respectively connected to opposite ends of the first mounting surface 131 and the second mounting surface, so that the first mounting surface 131, the second mounting surface, the third mounting surface 133 and the fourth mounting surface together enclose the peripheral side surfaces of the strain beam. Moreover, the planes where the first mounting surface 131, the second mounting surface, the third mounting surface 133 and the fourth mounting surface are located are all set to intersect with the direction of the Z-axis torque. Wherein, a strain gauge 140 is mounted on each of the first mounting surface 131, the second mounting surface, the third mounting surface 133 and the fourth mounting surface. Of course, in some embodiments, the third mounting surface 133 and the fourth mounting surface are parallel to the direction of the Z-axis torque. Therefore, even if strain gauges 140 are provided on the third mounting surface 133 and the fourth mounting surface, their force-induced deformations are the same, and the effect of error elimination cannot be achieved or the error elimination effect can be ignored. Thus, in this case, strain gauges 140 may not be provided on the third mounting surface 133 and the fourth mounting surface.

[0024] In one embodiment, each strain gauge 140 includes at least one strain gauge (not labeled in the figure). Wherein, the strain gauge undergoes mechanical deformation under the action of an external force, and its resistance parameter changes accordingly. Therefore, when the strain beam 130 is stressed and deformed, the strain gauge generates mechanical deformation, so that the Z-axis torque can be measured through the change amount of the resistance parameter of the strain gauge. Wherein, the resistance parameter can be a resistance value or a resistivity, which is not limited herein. Wherein, the strain gauge can be a semiconductor strain gauge or a metal strain gauge, which is not limited herein. The strain gauge 140 of this embodiment includes at least one strain gauge, so the structure of the strain gauge 140 of this embodiment is simple; in addition, the use technology of the strain gauge is mature, which can ensure the working stability of the joint torque sensor 10.

[0025] In other embodiments, in order to improve the detection accuracy of the joint torque sensor 10, the strain gauge 140 may further include a plurality of strain gauges. For example, the strain gauge 140 includes 2 strain gauges, or 3 strain gauges, or 4 strain gauges, etc., which is not limited herein. Wherein, the plurality of strain gauges can be symmetrically arranged on the same mounting surface, so that the plurality of strain gauges can measure the deformation degrees of different positions of the strain beam 130 on the mounting surface, and the detection accuracy of the joint torque sensor 10 can be improved. For example, the strain gauge 140 includes two strain gauges, and the two strain gauges are arranged adjacent to each other in the same direction; or the two strain gauges are arranged at an angle. For example, the two strain gauges are at 45° on the same mounting surface and the opening faces the outer ring portion 120; the strain gauge 140 includes four strain gauges, and the four strain gauges can be distributed in a rectangular shape on the mounting surface or evenly distributed in a circular shape on the mounting surface, which is not limited herein.

[0026] In one embodiment, the strain gauge includes a strain gauge with a feather-shaped wire grid, and the included angle between the wire grid of the strain gauge and the strain beam 130 in the direction from the inner ring portion 110 to the outer ring portion 120 is 45°. The strain gauge with a feather structure can expand the contact area with the strain beam 130, make the strain transfer to the wire grid more evenly, and improve the detection accuracy of the joint torque sensor 10.

[0027] In one embodiment, concave mounting grooves (not shown in the figure) are provided on both the first mounting surface 131 and the second mounting surface of each strain beam 130. The strain gauge is disposed in the mounting groove. The mounting groove is used to position the sticking position of the strain gauge, prevent the strain gauge from being stuck obliquely, and at the same time improve the stress distribution of the sticking surface and enhance the linearity of the joint torque sensor 10. In other embodiments, if strain gauges are provided on both the third mounting surface and the fourth mounting surface of the strain beam 130, then concave mounting grooves are provided on both the third mounting surface and the fourth mounting surface.

[0028] In one embodiment, the strain gauge 140 is disposed near the middle position of the mounting surface. Herein, the middle position of the mounting surface can be regarded as the middle position of the structure of the strain beam 130. The degree of deformation of the strain beam 130 at the non-connected end is stronger than that at the connected end of the strain beam 130. Therefore, disposing the strain gauge 140 near the middle position of the mounting surface can improve the detection accuracy of the joint torque sensor 10. For example, the center of the strain gauge 140 coincides with the center of the mounting surface; or the deviation dimension between the center of the strain gauge 140 and the center of the mounting surface is negligible.

[0029] In one embodiment, in order to improve the detection accuracy of the joint torque sensor 10, along the positive projection direction of each first mounting surface 131 of the strain beam 130 towards the corresponding second mounting surface, the strain gauges on the first mounting surface 131 and the second mounting surface of each strain beam 130 overlap each other. It can be understood that the strain beam 130 is a structure with a certain thickness. In the thickness direction of the strain beam 130, the two strain gauges 140 on the first mounting surface 131 and the second mounting surface of the same strain beam 130 are arranged in alignment, that is, the setting positions of the strain gauges 140 in the thickness direction of the strain beam 130 are aligned, so that the deformation degrees of the two strain gauges 140 are the same, thereby reducing the error between the positive strain and the negative strain of the two strain gauges 140, and further improving the detection accuracy of the joint torque sensor 10. The "same" described in this embodiment means the situation where it can be ignored within the error range.

[0030] In one embodiment, the strain beams 130 are evenly distributed around the center of the inner ring portion 110, and the two corresponding strain beams 130 are centrosymmetric with respect to the center of the circle. Therefore, the strain beams 130 in this embodiment can conduct force in a balanced manner, so that the deformation degree of each strain beam 130 is the same within the error range, thereby improving the detection accuracy of the joint torque sensor 10.

[0031] In one embodiment, the first mounting surface 131 and the second mounting surface of each strain beam 130 are disposed opposite to each other along the axial direction of the inner ring portion 110. Each strain gauge 140 on each first mounting surface 131 and each second mounting surface is provided with two strain gauges. The first mounting surface 131 and the second mounting surface of this embodiment are arranged along the axial direction of the inner ring portion 110, that is, the strain gauges 140 on each strain beam 130 are arranged along the axial direction of the inner ring portion 110. Therefore, the deformation degrees of the strain gauges 140 on the same strain beam 130 are equal within the error range. So the detection results of the first mounting surface 131 and the second mounting surface can cancel each other out, that is, it can cancel the errors generated by other bending moments and torques on the torque, thereby improving the detection accuracy of the joint torque sensor 10. In addition, each strain gauge 140 on each first mounting surface 131 and each second mounting surface is provided with two strain gauges, so that the two strain gauges can measure the deformation degrees of different positions of the strain beam 130 on the mounting surface, which can further improve the detection accuracy of the joint torque sensor 10.

[0032] In one embodiment, the joint torque sensor 10 further includes a bridge 150 formed by connecting strain gauges. The strain gauges of each bridge 150 are arranged on the first mounting surface 131 and the second mounting surface of at least two strain beams 130, and the bridge arms of the bridge 150 at least include the strain gauges on the first mounting surface 131 and the second mounting surface of the same strain beam 130.

[0033] It can be understood that the strain gauge can be regarded as a resistor, and the strain gauges arranged on the first mounting surface 131 and the second mounting surface of at least two strain beams 130 form a bridge circuit. Among them, the bridge 150 is a Wheatstone bridge, and the bridge arms of the bridge 150 at least include the strain gauges on the first mounting surface 131 and the second mounting surface of the same strain beam 130. Specifically, the strain gauges on the first mounting surface 131 and the second mounting surface of the same strain beam 130 are connected in series.

[0034] Different from the method of setting a single strain beam with a single bridge, in this embodiment, the strain gauges of the bridge 150 are arranged on the first mounting surface 131 and the second mounting surface of at least two strain beams 130. Therefore, the requirements for the setting of the strain gauges are lower, and the installation of the strain gauges is easier. As a result, the manufacturing of the joint torque sensor 10 is simpler. In addition, through the error elimination method of the bridges corresponding to the upper and lower beams, since it is very difficult to ensure complete radial symmetry in actual application of the upper and lower strain beams, it is almost impossible to ensure complete positive and negative compensation, and the error compensation effect is poor. Compared with the error elimination method of the bridges corresponding to the upper and lower beams, in this application, the positive and negative strain results of the strain gauges on the first mounting surface 131 and the second mounting surface of the same strain beam 130 are symmetric. Therefore, the corresponding resistances can compensate and cancel each other, and can cancel the errors generated by other bending moments and torques on the Z-axis torque, thereby improving the detection accuracy of the joint torque sensor 10.

[0035] In one embodiment, the number of bridges 150 is the same as the number of strain gauges provided in each strain gauge 140. Each bridge 150 is formed by connecting one strain gauge on the first mounting surface 131 of all strain beams 130 and one strain gauge on the second mounting surface of all strain beams 130. That is, on each strain gauge 140, the strain gauges at the same position form a bridge 150.

[0036] In one embodiment, the strain gauges on the bridge 150 are electrically connected by copper wires. Copper has good electrical conductivity and low resistivity, which can reduce signal transmission loss and improve the detection accuracy of the joint torque sensor 10.

[0037] In one embodiment, each strain gauge 140 includes a first strain gauge and a second strain gauge. Among them, the first strain gauges corresponding to the first mounting surface 131 and the second mounting surface of at least two strain beams 130 are connected to form a first bridge 151 (see Figure 3 ). The second strain gauges corresponding to the first mounting surface 131 and the second mounting surface of at least two strain beams 130 are connected to form a second bridge 152 (see Figure 3 ). Among them, the first bridge 151 and the second bridge 152 are connected in parallel (see Figure 5Understandably, each strain gauge 140 in this embodiment includes two strain gauges. Therefore, the joint torque sensor 10 in this embodiment includes two bridges 150. Among them, on each strain beam 130, the first strain gauge on the first mounting surface 131 and the first strain gauge on the second mounting surface form a bridge 150, and the second strain gauge on the first mounting surface 131 and the second strain gauge on the second mounting surface form a bridge 150. It is worth noting that the setting position of the first strain gauge on the first mounting surface 131 is opposite to the setting position of the first strain gauge on the second mounting surface, and the setting position of the second strain gauge on the first mounting surface 131 is opposite to the setting position of the second strain gauge on the second mounting surface.

[0038] Between the two first strain gauges of the bridge arms on the first bridge 151 and the second bridge 152 in this embodiment, mutual compensation and cancellation can be achieved; in addition, the first bridge 151 and the second bridge 152 are arranged in parallel, and secondary mutual cancellation can be achieved. Therefore, the joint torque sensor 10 in this embodiment can further improve the detection accuracy.

[0039] For example, the strain gauge 140 includes a first strain gauge and a second strain gauge. On the same strain beam 130, the first strain gauge of the strain gauge installed on the first mounting surface 131 is numbered A, and the second strain gauge is numbered A'; the first strain gauge of the strain gauge installed on the second mounting surface is numbered a, and the second strain gauge is numbered a'. Among them, the strain gauge A and the strain gauge a are arranged correspondingly, and the strain gauge A' and the strain gauge a' are aligned. Similarly, if the joint torque sensor 10 has four strain beams 130, the strain gauges of the strain gauges 140 of the 4 strain beams 130 include: the strain gauge A and the strain gauge a, the strain gauge A' and the strain gauge a'; the strain gauge B and the strain gauge b, the strain gauge B' and the strain gauge b'; the strain gauge C and the strain gauge c, the strain gauge C' and the strain gauge c'; the strain gauge D and the strain gauge d, the strain gauge D' and the strain gauge d'.

[0040] Refer to Figure 3 , Figure 3 is the circuit schematic diagram of the first embodiment of the bridge provided by this application. If the strain gauge 140 includes one strain gauge, the bridge arms of the bridge 150 can refer to the structure of the first bridge 151 or the second bridge 152: the strain gauge A and the strain gauge a are connected in series as the first bridge arm, or the strain gauge A' and the strain gauge a' are connected in series as the first bridge arm; the strain gauge B and the strain gauge b are used as the second bridge arm, and the strain gauge B' and the strain gauge b' are used as the second bridge arm; the strain gauge C and the strain gauge c are connected in series as the third bridge arm, or the strain gauge C' and the strain gauge c are connected in series as the third bridge arm'; the strain gauge D and the strain gauge d are connected in series as the fourth bridge arm, or the strain gauge D' and the strain gauge d' are connected in series as the fourth bridge arm.

[0041] Refer to Figure 4 , Figure 4It is a schematic circuit diagram of the second embodiment of the bridge provided by this application. If the strain gauge 140 includes two strain gauges, the bridge arms of the bridge 150 can be: strain gauge A, strain gauge a, strain gauge B, and strain gauge b are connected in series as the first bridge arm; strain gauge A', strain gauge a', strain gauge D, and strain gauge d are connected in series as the second bridge arm; strain gauge C, strain gauge c, strain gauge B', and strain gauge b' are connected in series as the third bridge arm; strain gauge C', strain gauge c, strain gauge D', and strain gauge d' are connected in series as the fourth bridge arm.

[0042] Refer to Figure 5 , Figure 5 It is a schematic circuit diagram of the third embodiment of the bridge provided by this application. The input ends of the first bridge 151 and the second bridge 152 are arranged in parallel, and the output ends of the first bridge 151 and the second bridge 152 are arranged in parallel.

[0043] It should be noted that if strain gauges are provided on both the third mounting surface and the fourth mounting surface of the strain beam 130, after the correspondingly arranged strain gauges on the third mounting surface and the fourth mounting surface of the same strain beam 130 are connected in series, they are used as one bridge arm of the bridge 150 or are connected in series with other serially connected strain gauges to form one bridge arm of the bridge 150. That is, the connection method of the bridge 150 for the correspondingly arranged strain gauges on the third mounting surface and the fourth mounting surface of the same strain beam 130 is the same as that of the embodiments of the above bridge 150, which is not limited here.

[0044] This application provides a robot (not shown in the figure). The robot includes joints and a joint torque sensor 10. The joint torque sensor 10 is installed at the joints to detect the forces received by the joints. Among them, the joint torque sensor 10 is any one of the above embodiments of the joint torque sensor. For its specific working process, refer to the above embodiments of the joint torque sensor, which will not be elaborated here.

[0045] Among them, the robot can be an overall movable robot, or the robot can be a partially movable robot. For example, the partially movable robot can be a robotic arm.

[0046] The above are only the implementation manners of this application, and do not limit the patent scope of this application. Any equivalent structure or equivalent process transformation made using the content of the specification and drawings of this application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of this application.

Claims

1. A joint torque sensor, characterized in that, Comprising: At least two strain beams, each of the strain beams including a first mounting surface and a second mounting surface arranged oppositely; Strain gauges, with the strain gauges mounted on each of the first mounting surfaces and each of the second mounting surfaces; wherein, The planes where each of the first mounting surfaces and each of the second mounting surfaces are located intersect with the direction of the torque; Wherein, the strain gauge includes at least one strain gauge element, and the joint torque sensor further includes a bridge formed by connecting the strain gauge elements, and the bridge arms of the bridge at least include the strain gauge elements arranged correspondingly and in series on the first mounting surface and the second mounting surface of the same strain beam.

2. The joint torque sensor according to claim 1, wherein The number of the bridges is the same as the number of the strain gauge elements provided in each strain gauge; Each of the bridges is formed by connecting one of the strain gauge elements on the first mounting surface of all the strain beams and one of the strain gauge elements on the second mounting surface of all the strain beams.

3. The joint torque sensor according to claim 1, wherein Along the positive projection direction of the first mounting surface of each strain beam towards the corresponding second mounting surface, the strain gauge elements on the first mounting surface and the second mounting surface of each strain beam coincide with each other.

4. The joint torque sensor according to claim 1, characterized in that, The bridge includes a first bridge and a second bridge, and each strain gauge includes a first strain gauge element and a second strain gauge element; wherein, The first strain gauge elements corresponding on the first mounting surfaces and the second mounting surfaces of at least two of the strain beams are connected to form the first bridge, and the bridge arms of the first bridge at least include the first strain gauge elements on the first mounting surface and the second mounting surface of the same strain beam; The second strain gauge elements corresponding on the first mounting surfaces and the second mounting surfaces of at least two of the strain beams are connected to form the second bridge, and the bridge arms of the second bridge at least include the second strain gauge elements on the first mounting surface and the second mounting surface of the same strain beam; wherein, the first bridge and the second bridge are in parallel connection.

5. The joint torque sensor according to claim 1, wherein The joint torque sensor includes an inner ring part and an outer ring part arranged concentrically, wherein, the inner ring part is located inside the outer ring part; Each of the strain beams is connected to the inner ring part and the outer ring part.

6. The joint torque sensor according to claim 5, characterized in that, The strain beams are evenly distributed around the center of the inner ring part, and two corresponding strain beams are arranged centrosymmetrically with respect to the center.

7. The joint torque sensor according to claim 5 or 6, characterized in that, The first mounting surface and the second mounting surface of each strain beam are arranged oppositely along the axial direction of the inner ring part; Two strain gauge elements are provided on each of the strain gauges on each of the first mounting surfaces and each of the second mounting surfaces.

8. A robot, comprising joints, characterized in that, The robot further includes the joint torque sensor according to any one of claims 1-7, and the joint torque sensor is mounted at the joint.

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