CN206048259U - A kind of two dimension clamping force checking device - Google Patents

Abstract

The utility model discloses a two-dimensional clamping force detection device, which aims at detecting the sense of touch and sliding between a clamper and an object. The detection device includes two extended octagonal rings, the front ring has a left earring and a right earring, and the rear ring also has a left earring and a right earring. The shape and size of the earrings are the same as that of the front ring; There is a through slot; the detection device is left and right symmetrical, with a through hole on each side, the axes of the two holes are parallel, and there is a convex through slot between the two holes; the upper left plane and the upper right plane of the rear ring are respectively equipped with a first strain gauge, and the lower left plane A second strain gauge is provided on the left and right planes of the front ring respectively, a third strain gauge is respectively provided on the left plane and the right plane of the front ring, and a fourth strain gauge is respectively provided on the inner wall of the left through hole and the right through hole. The structure of the two-dimensional clamping force detection device is simple in structure and small in size, and can not only measure normal pressure and tangential force, but also measure slip sensation.

Description

A two-dimensional clamping force detection device

technical field

The utility model relates to a detection device, in particular to a two-dimensional clamping force detection device.

Background technique

Grasping soft or crispy objects is a challenge to the gripping performance of dexterous manipulators. In order to allow the manipulator to properly adjust the grasping force according to the tactile information of the hand like a human hand, and achieve a stable grasping process without slipping, it is necessary to be able to grasp the tactile information and slip information during grasping in real time. It can sense slip and tactile information at the same time, and the detection device adopted has a simple structure, strong anti-interference ability, and low cost is an urgent problem to be solved.

At present, most grippers calculate the clamping force indirectly through the motor current; there are also slip sensors made of materials such as PVDF or force-sensitive rubber between the gripper and the object; a pressure sensor is installed at the contact point between the gripper and the object to directly detect the clamping force. contact pressure between the holder and the object. There is also a method of combining a slip sensor with a pressure sensor to predict the sliding of an object. An optimal grasp is one that senses both touch and slip. The predecessors used the multi-sensor combination method, the multi-sensor structure is complicated, the anti-interference ability is weak, and the manufacturing cost is high.

Therefore, it is very necessary to use a high-sensitivity detection device that can detect both sliding and tactile sensations at the end of the manipulator.

Contents of the invention

Technical problem: The technical problem to be solved by this utility model is to provide a two-dimensional clamping force detection device with simple structure, simple manufacture and low cost, which can detect both clamping force and tangential force and slip sensation.

Technical solution: In order to solve the above technical problems, the technical solution of the utility model is as follows:

A two-dimensional clamping force detection device is characterized in that it includes a front ring 1111 and a rear ring 2222; the front ring 1111 has a left earring 111 and a right earring 222, on the first side 1 of the left earring 111 and the right earring 222 A first strain gauge 11 is attached to the second side 2 of the second side respectively; the rear ring 2222 also has a left earring 333 and a right earring 444, and the third side 3 of the left earring 333 and the fourth side 4 of the right earring 444 are respectively attached with A third strain gauge 33 is attached to a fourth strain gauge 44 on the fifth side 5 of the left earring 333 and the sixth side 6 of the right earring 444 respectively.

There is a first through groove 101 between the left earring 111 of the front ring 1111 and the left earring 333 of the rear ring 2222, and there is also an identical second through groove between the right earring 222 of the front ring 1111 and the right earring 444 of the rear ring 2222. Groove 102; The detection device is left-right symmetrical, and there is a first through hole 201 on the left side, and a second through hole 202 is arranged on the right side, and there is a convex groove 301 between the first through hole 201 and the second through hole 202), and the first through hole Second strain gauges 22 are attached to the left inner wall of 201 and the right inner wall of the second through hole 202 respectively.

Beneficial effects: According to the characteristics of octagonal rings deformed by force, the utility model adopts two mutually parallel extended octagonal ring structures to realize the measurement of clamping force, tangential force and sliding sensation. There is a through slot between the front ring and the rear ring, which reduces the working width of the octagonal ring and increases the sensitivity of the detection device. The convex groove in the middle of the detection device has the function of overload protection for the detection device. The detection device has a simple structure and a simple manufacturing process. The processing is basically opening and slotting, and the volume is small. It is suitable for installation at the end of the gripper of the manipulator and is suitable for large-scale promotion. The utility model adopts two full-bridge Wheatstone bridges to collect signals, increases the sensitivity of the detection device, and provides good conditions for slip signal collection. The octagonal ring itself has the characteristics of structural decoupling, which reduces the influence and coupling between the two forces. The front ring of the utility model detects clamping force, and the rear ring detects tangential force and slippery feeling. The detection device has the characteristics of modularization, and its measuring circuit can be independently debugged, which simplifies the workload.

Description of drawings

Fig. 1 is a structural schematic diagram of a two-dimensional clamping force detection device of the present invention

In the picture are: front ring 1111, rear ring 2222, front ring left earring 111, front ring right earring 222, rear ring left earring 333, rear ring right earring 444, first side 1, second side 2, third side 3 , the fourth side 4, the fifth side 5, the sixth side 6, the first strain gauge 11, the second strain gauge 22, the third strain gauge 33, the fourth strain gauge 44, the first through groove 101, the second through groove 102 , the first through hole 201 , the second through hole 202 , and the convex groove 301 .

Figure 2 is a force analysis diagram of the utility model's two-dimensional clamping force detection device

Figure 3 is a schematic diagram of installation of the utility model on the holder

In the figure, there are: a gripper 1, a claw 2, and a two-dimensional gripping force detection device 3.

detailed description

The invention will be described in further detail below in conjunction with the accompanying drawings.

With reference to Fig. 1, a kind of two-dimensional clamping force detecting device comprises front ring 1111 and rear ring 2222; A first strain gauge 11 is attached to the second side 2 of the second side respectively; the rear ring 2222 also has a left earring 333 and a right earring 444, and the third side 3 of the left earring 333 and the fourth side 4 of the right earring 444 are respectively attached with A third strain gauge 33 is attached to a fourth strain gauge 44 on the fifth side 5 of the left earring 333 and the sixth side 6 of the right earring 444 respectively. There is a first through groove 101 between the left earring 111 of the front ring 1111 and the left earring 333 of the rear ring 2222, and there is also an identical second through groove between the right earring 222 of the front ring 1111 and the right earring 444 of the rear ring 2222. Slot 102; the detection device is left-right symmetrical, with a first through-hole 201 on the left, a second through-hole 202 on the right, a convex groove 301 between the first through-hole 201 and the second through-hole 202, and the first through-hole 201 A second strain gauge 22 is attached to the left inner wall of the second through hole 202 and the right inner wall of the second through hole 202 respectively.

The working principle of the two-dimensional clamping force detection device of this structure is:

During use, referring to FIG. 3 , the bottom surface of the detection device is installed on the claw 2 , and the claw 2 is installed on the holder 1 . When the gripper 1 is working, it drives the claw 2 to move, and the detection device 3 is deformed under force, which will cause the resistance value of the strain gauge to change, and the changed resistance value represents the magnitude of the force. Specifically, referring to Figure 1, the force coordinates are shown in the figure. The positive directions of the two coordinate axes of X and Y correspond to the positive directions of the acting forces F _x and F _y at the same time. F _x corresponds to tangential force and slip sensation, and F _y corresponds to clamping force. The bottom end of the octagonal ring composed of the front ring 1111 and the rear ring 2222 is fixed, and the top end is subjected to the clamping force F _y and the tangential force F _x generated by the friction between the object and the detection device. Referring to Figure 2, since the structure of the octagonal ring is symmetrical and similar to a circular ring, according to the theoretical calculation of the circular ring, the bending moment at any section is:

Then the surface strain of the ring becomes:

In the formula, t is the thickness of the octagonal ring, r is the average diameter of the octagonal ring, and E is the elastic modulus of the material. It can be seen that when θ=90°, the bending moment generated by F _x is 0, and the ring surface strain is only related to F _y . When θ=39.4° or θ=140.6°, the bending moment generated by F _y is 0, and the ring surface strain Relevant only to F _x .

Regarding the stress analysis of the extended octagonal ring, since the early traditional design method used the method of elastic mechanics, the established mechanical model was too simplified and the calculation accuracy was low, which could not meet the actual situation. In order to reduce the two-way force coupling error, the utility model uses Ansys workbench to conduct finite element analysis, accurately find the strain nodes, and find the best patching position of the strain gauge. Finally, it is determined that a first strain gauge 11 is attached to the first side 1 of the left earring 111 of the front ring 1111 and the second side 2 of the right earring 222 at θ=36.6°; 201 and the θ=133.6° of the second through hole 202 respectively paste a second strain gauge 22; on the third side 3 of the left earring 333 of the rear ring 2222 and the fourth side 4 of the right earring 4 of the rear ring 222, θ=96.6 A third strain gauge 33 is pasted at °; a fourth strain gauge 44 is respectively pasted at θ=97.6° on the fifth side 5 of the left earring of the rear ring 2222 and the sixth side 6 of the right earring of the rear ring 222.

The stress and strain on the surface of the octagonal ring will change the resistance values of the first strain gauge 11 and the second strain gauge 22, break the balance of the bridge, and convert it into a circuit output. Through calibration, the measurement of the clamping force F _y can be realized; similarly, the third The strain gauge 33 and the fourth strain gauge 44 can measure the tangential force _Fx and the sliding sensation.

Claims (2)

1. A two-dimensional clamping force detection device, characterized in that it comprises a front ring (1111) and a rear ring (2222); The front ring (1111) has a left earring (111) and a right earring (222), and a The first strain gauge (11); the rear ring (2222) also has a left earring (333) and a right earring (444), on the third side (3) of the left earring (333) and the fourth side of the right earring (444) A third strain gauge (33) is attached to the side (4) respectively, and a fourth strain gauge is respectively attached to the fifth side (5) of the left earring (333) and the sixth side (6) of the right earring (444) (44), There is a first through groove (101) between the left earring (111) of the front ring (1111) and the left earring (333) of the back ring (2222), and the right earring (222) of the front ring (1111) and the back ring There is also an identical second through-slot (102) between the right earring (444) of (2222); the detection device is left-right symmetrical, and a first through-hole (201) is arranged on the left side, and a second through-hole (202) is arranged on the right side, There is a convex groove (301) between the first through hole (201) and the second through hole (202), and the left inner wall of the first through hole (201) and the right inner wall of the second through hole (202) are pasted with the first Two strain gauges (22). 2. The two-dimensional clamping force detection device according to claim 1, wherein the detection device is made of aluminum alloy.