Autonomous calibration platform for modular joint torque sensor
Technical Field
The invention belongs to the field of joint torque sensor calibration.
Background
Along with the development of the robot technology, the requirements on the mechanical arm are higher and higher, the mechanical arm joint is generally provided with a torque sensor, and the torque is accurately controlled by matching with a control system. The calibration of the mechanical arm joint torque sensor needs stable torque input equipment, high-precision torque detection equipment and the like, the existing calibration platform generally adopts a manual loading method, the input torque is unstable, the data acquisition amount is small, the successive loading is troublesome, and dynamic testing cannot be carried out. There are also methods of inputting torque by motor stalling, etc., the input value is unstable, and the input value needs to be detected and read by a torsion meter, and the accuracy of the numerical value is affected by the precision of the torsion meter. Therefore, there is a need to solve the above problems.
Disclosure of Invention
The invention provides an autonomous calibration platform for a modular joint torque sensor, and aims to solve the problems that a manual torque loading method is small in data collection amount and cannot perform dynamic testing, and the accuracy of an input torque value is low by a motor locked-rotor input torque method.
The self-calibration platform is used for calibrating a to-be-calibrated torque sensor 15-1 in a tested joint 15 and comprises a brake 1, a brake seat 2, a main coupler 3, a first hollow sliding ring 4, a hollow sliding ring connecting shaft 5, a torque verification sensor 6, a torque verification sensor seat 7, a torque verification sensor connecting shaft 8, an auxiliary coupler 9, a cylindrical closed box body 10, a transmission shaft 11 and a base 12;
the hollow slip ring connecting shaft 5, the torque verification sensor connecting shaft 8 and the transmission shaft 11 are hollow shafts; a data transmission line of the torque sensor 15-1 to be calibrated is led out from the hollow shaft;
the brake 1, the main coupling 3, the moment checking sensor 6, the auxiliary coupling 9 and the cylindrical closed box 10 are sequentially arranged above the base 12;
the brake 1 is fixed on the base 12 through the brake seat 2;
the cylindrical closed box body 10 is fixed on a base 12 through a workpiece fixing seat 13;
an output shaft of the brake 1 is fixedly connected with one end of a main coupler 3, the other end of the main coupler 3 is fixedly connected with one end of a hollow sliding ring connecting shaft 5, a first hollow sliding ring 4 is sleeved on the hollow sliding ring connecting shaft 5, an inner ring of the first hollow sliding ring 4 rotates along with the hollow sliding ring connecting shaft 5, the other end of the hollow sliding ring connecting shaft 5 is fixedly connected with one end of a torque verification sensor connecting shaft 8 through a torque verification sensor 6, the other end of the torque verification sensor connecting shaft 8 is fixedly connected with one end of a transmission shaft 11 through an auxiliary coupler 9, and the other end of the transmission shaft 11 is used for receiving input torque;
the cylindrical closed box body 10 is internally provided with a joint 15 to be measured, the transmission shaft 11 penetrates through the cylindrical closed box body 10 and the joint 15 to be measured, and the transmission shaft 11 drives the joint 15 to be measured to rotate;
the free end of a data transmission line of the torque verification sensor 6 is connected with the rotating end of the first hollow slip ring 4;
the fixed end of the first hollow slip ring 4 is fixed on the base 12 through the hollow slip ring seat 14;
the moment verification sensor 6 is rotationally connected with the moment verification sensor seat 7 through a bearing, and the moment verification sensor seat 7 is fixed on the base 12.
Preferably, the autonomous calibration platform facing the modular joint torque sensor further comprises a pulley 16;
the pulley 16 is fixed at one end of the transmission shaft 11 through a thin-wall deep groove ball bearing 17;
a cable 18 is wound around the pulley 16, and the cable 18 is used for loading an object.
Preferably, the secondary coupling 9 is a diaphragm coupling or a universal coupling.
Preferably, the autonomous calibration platform facing the modular joint torque sensor further comprises a hat-type slip ring 19;
the cap type slip ring 19 is fixed on the base 12 through a cap type slip ring seat 20;
the free end of the data transmission line of the torque sensor 15-1 to be calibrated is connected with the rotating end of the cap type slip ring 19.
Preferably, the cylindrical enclosure 10 is formed by two abutting drums;
connecting plates are arranged on the butt joint end surfaces of the two butt joint drums, the connecting plate close to the auxiliary coupling 9 is an output connecting plate 21, and the connecting plate far away from the auxiliary coupling 9 is an input connecting plate 22;
the output connecting plate 21 and the input connecting plate 22 are fixedly connected with the tested joint 15 through a flange 23.
Preferably, the base 12 is provided with a through hole 12-1, and the wire rope 18 can pass through the through hole 12-1.
Preferably, the brake 1 is a magnetic particle brake.
Principle analysis: the invention can be used for the autonomous calibration and the unbalance loading test of the torque sensor in the modular joint, and can dynamically calibrate the torque sensor 15-1 to be calibrated under the condition that the modular joint continuously rotates. The motor of control modularization joint is rotatory according to certain law, and transmission shaft 11 takes place to rotate, through vice coupling 9, moment check sensor connecting axle 8, moment check sensor 6, hollow sliding ring connecting axle 5, main coupling 3 drive stopper 1 is rotatory, stopper 1 can provide the load of constant torque, give stopper 1 multiunit input instruction through MATLAB GUI, gather the moment size that moment check sensor 6 measured simultaneously to give the moment sensor of modularization joint with numerical value, thereby realize autonomic demarcation and dynamic calibration.
When an offset load test is performed: when the calibration of the torque sensor 15-1 to be calibrated is finished, loads with different masses are hung on the steel wire rope 18, unbalance loads are transmitted to the output flange 16-1 through the pulley 16, the thin-wall deep groove ball bearing 17, the cylindrical closed box body 10 and the output connecting plate 14, and as the adopted diaphragm coupling or universal coupling can only transmit torque and can freely rotate in the radial direction, all the applied unbalance loads act on the torque sensor 15-1 to be calibrated, the mass of the steel wire rope 18 for hanging the weights is changed to apply multiple groups of unbalance loads, and the torque value output by the calibrated torque sensor is recorded, so that the influence of the unbalance loads on the modular joint torque sensor is obtained.
The autonomous calibration platform for the modular joint torque sensor has the advantages that the autonomous calibration platform for the modular joint torque sensor can be used for autonomous calibration of the modular joint torque sensor, loads are not required to be added manually, the data volume of autonomous calibration is improved by 20%, and the accuracy of a fitting curve of the autonomous calibration platform is improved by 20%.
The invention can dynamically calibrate the torque sensor 15-1 to be calibrated under the condition of continuous rotation of the modular joint.
The other end of the transmission shaft 11 directly receives the input torque, the automatic calibration platform has a good transmission effect, and the numerical accuracy of the input torque is not influenced by the automatic calibration platform.
Drawings
FIG. 1 is a schematic three-dimensional structure diagram of an autonomous calibration platform facing a modular joint torque sensor;
FIG. 2 is a front cross-sectional view of FIG. 1;
FIG. 3 is a top view of FIG. 1;
fig. 4 is a schematic three-dimensional structure of the measured joint 15 with the flange 23.
Detailed Description
The first embodiment is as follows: the embodiment is described with reference to fig. 1 to 4, and the autonomous calibration platform facing the modular joint torque sensor in the embodiment is used for calibrating a torque sensor 15-1 to be calibrated in a tested joint 15, and comprises a brake 1, a brake seat 2, a main coupler 3, a first hollow sliding ring 4, a hollow sliding ring connecting shaft 5, a torque verification sensor 6, a torque verification sensor seat 7, a torque verification sensor connecting shaft 8, an auxiliary coupler 9, a cylindrical closed box 10, a transmission shaft 11 and a base 12;
the hollow slip ring connecting shaft 5, the torque verification sensor connecting shaft 8 and the transmission shaft 11 are hollow shafts; a data transmission line of the torque sensor 15-1 to be calibrated is led out from the hollow shaft;
the brake 1, the main coupling 3, the moment checking sensor 6, the auxiliary coupling 9 and the cylindrical closed box 10 are sequentially arranged above the base 12;
the brake 1 is fixed on the base 12 through the brake seat 2;
the cylindrical closed box body 10 is fixed on a base 12 through a workpiece fixing seat 13;
an output shaft of the brake 1 is fixedly connected with one end of a main coupler 3, the other end of the main coupler 3 is fixedly connected with one end of a hollow sliding ring connecting shaft 5, a first hollow sliding ring 4 is sleeved on the hollow sliding ring connecting shaft 5, an inner ring of the first hollow sliding ring 4 rotates along with the hollow sliding ring connecting shaft 5, the other end of the hollow sliding ring connecting shaft 5 is fixedly connected with one end of a torque verification sensor connecting shaft 8 through a torque verification sensor 6, the other end of the torque verification sensor connecting shaft 8 is fixedly connected with one end of a transmission shaft 11 through an auxiliary coupler 9, and the other end of the transmission shaft 11 is used for receiving input torque;
the cylindrical closed box body 10 is internally provided with a joint 15 to be measured, the transmission shaft 11 penetrates through the cylindrical closed box body 10 and the joint 15 to be measured, and the transmission shaft 11 drives the joint 15 to be measured to rotate;
the free end of a data transmission line of the torque verification sensor 6 is connected with the rotating end of the first hollow slip ring 4;
the fixed end of the first hollow slip ring 4 is fixed on the base 12 through the hollow slip ring seat 14;
the moment verification sensor 6 is rotationally connected with the moment verification sensor seat 7 through a bearing, and the moment verification sensor seat 7 is fixed on the base 12.
In the embodiment, the autonomous calibration platform for the modular joint torque sensor can be used for autonomous calibration of the modular joint torque sensor, the load does not need to be added manually, the data volume acquired by autonomous calibration is improved by 20%, and the precision of a fitting curve of the autonomous calibration platform is improved by 20%.
The invention can dynamically calibrate the torque sensor 15-1 to be calibrated under the condition of continuous rotation of the modular joint.
The other end of the transmission shaft 11 directly receives the input torque, the automatic calibration platform has a good transmission effect, and the numerical accuracy of the input torque is not influenced by the automatic calibration platform.
The second embodiment is as follows: the present embodiment is described with reference to fig. 1 to 4, and the present embodiment is different from the autonomous calibration platform facing the modular joint torque sensor described in the first embodiment in that the present embodiment further includes a pulley 16;
the pulley 16 is fixed at one end of the transmission shaft 11 through a thin-wall deep groove ball bearing 17;
a cable 18 is wound around the pulley 16, and the cable 18 is used for loading an object.
According to the embodiment, the influence of the unbalanced load on the precision of the modular joint torque sensor can be tested. When the influence of the unbalance loading is tested, loads with different masses are hung on the steel wire rope 18, the unbalance loading can be completely applied to the modularized tested joint 15, and the test is convenient.
The third concrete implementation mode: referring to fig. 1 to 4, the present embodiment is described, and the present embodiment is different from the autonomous calibration platform for a modular joint torque sensor described in the first or second embodiments in that the auxiliary coupling 9 is a diaphragm coupling or a universal coupling.
In the embodiment, the auxiliary coupler 9 is a diaphragm coupler or a universal coupler, so that when the independent calibration platform carries out the influence of unbalance loading on the precision of the modular joint torque sensor, the unbalance loading is completely applied to the torque sensor 15-1 to be calibrated, and the calibration accuracy of the torque sensor 15-1 to be calibrated is high.
The fourth concrete implementation mode: the present embodiment is described with reference to fig. 1 to 4, and the present embodiment is different from the autonomous calibration platform facing the modular joint torque sensor described in the first embodiment in that the present embodiment further includes a hat-type slip ring 19;
the cap type slip ring 19 is fixed on the base 12 through a cap type slip ring seat 20;
the free end of the data transmission line of the torque sensor 15-1 to be calibrated is connected with the rotating end of the cap type slip ring 19.
In this embodiment, the hat-type slip ring 19 is arranged in such a way that the data transmission lines of the torque sensor 15-1 to be calibrated are not twisted with each other when the joint 15 to be measured rotates.
The fifth concrete implementation mode: the present embodiment is described with reference to fig. 1 to 4, and the present embodiment is different from the autonomous calibration platform for a modular joint torque sensor described in the first embodiment in that the cylindrical closed box 10 is formed by two butted drums;
connecting plates are arranged on the butt joint end surfaces of the two butt joint drums, the connecting plate close to the auxiliary coupling 9 is an output connecting plate 21, and the connecting plate far away from the auxiliary coupling 9 is an input connecting plate 22;
the output connecting plate 21 and the input connecting plate 22 are fixedly connected with the tested joint 15 through a flange 23.
According to the embodiment, the influence of the unbalanced load on the precision of the modular joint torque sensor can be tested. When modular joint torque sensors with different diameters need to be replaced, the inner diameter of the flange 23 can be adjusted, and the disassembly is simple and convenient.
The sixth specific implementation mode: referring to fig. 1 to 4, the present embodiment is described, and the present embodiment is different from the autonomous calibration platform for a modular joint torque sensor described in the second embodiment in that a through hole 12-1 is formed in the base 12, and the wire rope 18 can pass through the through hole 12-1.
In this embodiment, the cable 18 can be loaded with weights of different heights without being affected by the base 12.
The seventh embodiment: the present embodiment is described with reference to fig. 1 to 4, and the present embodiment is different from the autonomous calibration platform for a modular joint torque sensor described in the first embodiment in that the brake 1 is a magnetic powder brake.
The structure of the autonomous calibration platform for a modular joint torque sensor according to the present invention is not limited to the specific structure described in each of the above embodiments, and may be a reasonable combination of the technical features described in each of the above embodiments.