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CN-115514258-B - Multi-motor synchronous force control method and system

CN115514258BCN 115514258 BCN115514258 BCN 115514258BCN-115514258-B

Abstract

The invention provides a multi-motor synchronous force control method and system, wherein the method comprises the steps of obtaining total expected force of a plurality of motors, calculating sub expected force of each motor according to characteristics of each motor in the plurality of motors, setting an outer feedback loop for controlling each motor to operate according to the corresponding sub expected force, taking a synchronicity error of each motor as a feedback item of the outer feedback loop, setting an inner feedback loop for controlling each motor to operate according to the corresponding sub expected force, and taking an output force error of each motor as a feedback item of the inner feedback loop. According to the scheme, on the premise of realizing accurate force control, the synchronism of the motion of multiple motors is guaranteed, high-power accurate force control output is realized, and the actual industrial requirements are met.

Inventors

  • HU JINGCHEN

Assignees

  • 上海新纪元机器人有限公司

Dates

Publication Date
20260508
Application Date
20220915

Claims (9)

  1. 1. A multi-motor synchronous force control method is characterized by comprising the steps of, Acquiring the total expected force of multiple motors; calculating sub expected forces of each motor according to the characteristics of each motor in the plurality of motors; setting an outer feedback loop for controlling each motor to run according to the corresponding sub expected force, and taking the synchronism error of each motor as a feedback item of the outer feedback loop; Setting an inner feedback loop for controlling each motor to run according to the corresponding sub expected force, and taking the output force error of each motor as a feedback item of the inner feedback loop; The feedback term using the output force error of each motor as the internal feedback loop specifically includes: measuring the deformation quantity of the springs arranged at the movable ends of the motors in real time to obtain the actual output force of the motors; and calculating the output force error of each motor according to the actual output force of each motor and the corresponding sub expected force, and taking the output force error as a feedback item of the inner feedback loop.
  2. 2. The method for controlling synchronous force of multiple motors according to claim 1, wherein the feedback term of the outer feedback loop is a synchronous error of each motor, and specifically comprises: measuring the displacement and the speed of each motor in real time through an encoder arranged in the motor; calculating the synchronism error of each motor according to the displacement and the speed of each motor; And taking the synchronicity error as a feedback term of the outer feedback loop.
  3. 3. The method of claim 2, further comprising presetting control parameters of the outer feedback loop; the synchronization error comprises a synchronization displacement error and a synchronization speed error; The control parameters of the outer feedback loop include a first parameter corresponding to the synchronous displacement error and a second parameter corresponding to the synchronous velocity error.
  4. 4. A multi-motor synchronous force control method according to claim 1, characterized by further comprising: And presetting control parameters of the inner feedback loop.
  5. 5. A method of synchronous force control of multiple motors according to any of claims 1-4, wherein the feedback signal of the inner feedback loop is updated at a first predetermined frequency, the feedback signal of the outer feedback loop is updated at a second predetermined frequency, The first preset frequency is greater than the second preset frequency.
  6. 6. The method of claim 5, wherein the feedback signal of the inner feedback loop is a first predetermined bandwidth, the feedback signal of the outer feedback loop is a second predetermined bandwidth, The first preset bandwidth is greater than the second preset bandwidth.
  7. 7. A multi-motor synchronous force control system based on the multi-motor synchronous force control method of any one of claims 1-6, comprising: An upper table top; the bottom plate is arranged opposite to the upper table top, and a plurality of motors are fixedly arranged on one side of the bottom plate facing the upper table top; An encoder is arranged in the motor, and the movable ends of the actuating mechanisms of the motor are connected with the upper table top through springs; And displacement sensors for measuring the deformation quantity of the springs are arranged on the sides of the springs.
  8. 8. The multi-motor synchronous force control system according to claim 7, wherein guide holes are formed in four corners of the upper table top, and guide rods matched with the guide holes are formed in four corners of the top surface of the bottom plate.
  9. 9. The multi-motor synchronous force control system of claim 7, wherein the plurality of motors are evenly distributed and of the same type.

Description

Multi-motor synchronous force control method and system Technical Field The invention relates to the technical field of motor control, in particular to a multi-motor synchronous force control method and system. Background In many industrial scenarios, there is a need for synchronous operation of multiple motors, for example, in a highly constrained mechanism, a large torque needs to be output, and if a single high-power motor cannot meet the installation requirement, multiple motors can be used to synchronously operate in parallel to meet the requirement. The synchronous operation of the motors has high requirements on the synchronism of the motors, and most of the current schemes only consider the position control mode of the synchronous operation of multiple motors, namely, each motor is driven to output the same expected motion trail. According to different control strategies, the method can be divided into equal control, master-slave control, adjacent coupling control, cross coupling control, virtual main shaft control, deviation coupling control and the like. However, the synchronous force control of multiple motors not only requires accurate force control, but also satisfies the displacement and speed synchronicity of each motor, which is equivalent to the force/position hybrid control of multiple motors, and has higher difficulty, and the traditional scheme for measuring the output torque of the motors through current or installing force sensors has limited application scenes because of overhigh cost. Therefore, a method capable of ensuring the motion synchronicity of multiple motors while precisely controlling force is needed. Disclosure of Invention The invention aims to provide a multi-motor synchronous force control method and system, which solve the problems of higher difficulty and over-high cost of multi-motor force/position hybrid control in the prior art. The technical scheme provided by the invention is as follows: The invention provides a multi-motor synchronous force control method, which comprises the steps of, Acquiring the total expected force of multiple motors; calculating sub expected forces of each motor according to the characteristics of each motor in the plurality of motors; setting an outer feedback loop for controlling each motor to run according to the corresponding sub expected force, and taking the synchronism error of each motor as a feedback item of the outer feedback loop; And setting an inner feedback loop for controlling each motor to run according to the corresponding sub expected force, and taking the output force error of each motor as a feedback item of the inner feedback loop. When high-power force control output is carried out, the target total expected force of a plurality of motors and the characteristics of each motor can be obtained, the sub expected force of each motor can be calculated, meanwhile, when each motor is controlled to operate according to the corresponding sub expected force, the outer feedback loop and the inner feedback loop are arranged, the synchronism error of each motor is used as a feedback item of the outer feedback loop, the output force error of each motor is used as a feedback item of the inner feedback loop, accurate force control can be realized in a limited space, the synchronism of movement of the plurality of motors is ensured, and more industrial requirements can be met. Specifically, by distributing the desired force profile of each motor with the total desired force and causing each motor to execute in accordance with the desired force, accurate control can be achieved and displacement and speed of the motors can be maintained with high synchronicity. In addition, control is realized through two loops, the inner loop is a high-speed force feedback loop, the control rate is designed according to the output force error of the motor, the motor is enabled to output according to the corresponding sub expected force, the outer loop is a low-speed motion synchronicity error loop, and the control rate is designed according to the displacement and speed difference of each motor, so that each motor further keeps synchronous operation. In some embodiments, the feedback term of the outer feedback loop, which includes the synchronization error of each motor, specifically includes: measuring the displacement and the speed of each motor in real time through an encoder arranged in the motor; calculating the synchronism error of each motor according to the displacement and the speed of each motor; And taking the synchronicity error as a feedback term of the outer feedback loop. When the synchronism error is calculated, the displacement and the speed of each motor can be measured in real time through an encoder arranged in the motor, and the synchronism error of each motor is calculated by comparing the displacement and the speed of each motor. In some embodiments, the method further comprises presetting control parameters of the outer feedback