A system and method for adjusting the force control accuracy of a motor

Abstract

The present invention discloses a system and method for adjusting the force control accuracy of a motor, and belongs to the technical field of electronic equipment testing. The above-mentioned system includes: a pressure amplifier, a pressure sensor, a motor, a motor driver, and a force control subsystem; the pressure sensor senses the pressure applied to the device under test; the pressure amplifier inputs the amplified pressure signal into the force control subsystem; the force control subsystem determines the first control parameter for controlling the motor according to the amplified pressure signal, and sends the first control parameter to the control execution unit, and the control execution unit controls the motor driver to drive the motor, adjusts the speed, rotation direction and current position of the motor, so that the pressure applied to the device under test reaches the target pressure value. The present invention provides technical support for application scenarios that require high-precision force control.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic device testing, and particularly relates to a system and method for adjusting the force control precision of a motor. Background Art

[0002] When testing products in the fields of computers, communications, consumer electronics, the automotive industry, and the medical industry, force control testing and monitoring of force feedback are required. When performing force control testing, it is necessary to make the continuous acting force of the actuator on the test device reach an accuracy of + / - 0.01 N of the target value to ensure the accuracy and reliability of the test. However, the current market situation brings two major challenges to users:

[0003] Firstly, the traditional motors widely used in the current market do not support force control functions themselves; secondly, the motor resources supporting force control in the market are scarce, and there are uneven force control precisions in important indicators. In view of the above, users face many problems such as design adaptation, cost, and time during the process of purchasing such products, which significantly increases the purchasing difficulty and the overall time cost of users. Summary of the Invention

[0004] The present invention provides a system and method for adjusting the force control precision of a motor, aiming to solve the technical problems that existing traditional motors do not support force control and the force control precision of motors that can support force control is insufficient.

[0005] In the first aspect of the present invention, a system for adjusting the force control precision of a motor is proposed, and the system includes:

[0006] A pressure amplifier, a pressure sensor, a motor, a motor driver, and a force control subsystem;

[0007] The pressure sensor is deployed on the device to be tested, and after the system for adjusting the force control precision of the motor finishes self-learning of the pre-pressing position, it senses the pressure applied on the device to be tested; the pressure amplifier amplifies the pressure signal obtained by the pressure sensor, and the amplified pressure signal is input into the force control subsystem; the force control subsystem determines a first control parameter for controlling the motor according to the amplified pressure signal, sends the first control parameter to the control execution unit, and the control execution unit controls the motor driver to drive the motor, and adjusts the rotation speed, rotation direction, and current position of the motor to make the pressure applied on the device to be tested reach the target pressure value;

[0008] The force control subsystem includes a host computer, a sampling unit, a micro control unit, and a control execution unit;

[0009] The microcontroller unit acquires the sampling signal and the target value set by the host computer, and calls the PID algorithm to output the control parameters; generates the first control parameter for controlling the motor based on the control parameters, and the control execution unit drives the motor based on the first control parameter; the sampling signal is obtained based on the amplified pressure signal acquired by the sampling unit.

[0010] The sampling unit includes a first sampling unit and a second sampling unit, and the sampling speed of the first sampling unit is greater than that of the second sampling unit; the first sampling unit and the second sampling unit are used alternately, the first sampling unit has multiple analog quantity acquisition interfaces, and the second sampling unit has a second RS485 communication interface; the sampling unit adjusts the sampling frequency based on the control instruction of the microcontroller unit.

[0011] The first sampling unit and the second sampling unit support the collaborative use of multiple pressure amplifiers; when multiple pressure amplifiers are used collaboratively, each analog quantity interface of the first sampling unit can be connected to a pressure amplifier for amplifying the pressure; the second RS485 communication interface of the second sampling unit can expand multiple connection paths, and each connection path is used to connect a pressure amplifier for amplifying the pressure.

[0012] For the system according to the first aspect of the present invention, after the system for adjusting the motor force control accuracy is initialized, the pre-pressing position self-learning is performed, and the method of the pre-pressing position self-learning is as follows:

[0013] The host computer sends the self-learning offset value set by the user to the microcontroller unit, and then sends the pre-pressing position self-learning instruction. The system for adjusting the motor force control accuracy controls the motor to start running, and acquires the value of the pressure amplifier in real time. When it is detected that the value of the pressure amplifier is equal to or greater than 1N, it is determined that the indenter of the mechanism connected to the motor has contacted the device to be measured, and a position adjustment with a deviation less than the preset threshold is performed on the motor, and the preset threshold is 1N; after the system for adjusting the motor force control accuracy continuously determines that the value of the pressure amplifier is within the preset threshold for 10 times, the position value corresponding to the current position of the motor is subtracted by the self-learning offset value as the pre-pressing position value, and the position corresponding to the pre-pressing position value is used as the pre-pressing position.

[0014] For the system according to the first aspect of the present invention, the control execution unit includes multiple pulse interfaces and a first RS485 communication interface, and the motor is connected to one of the multiple pulse interfaces or connected to the first RS485 communication interface; the control execution unit controls the motor driver to drive the motor based on the first control parameter, and feeds back the current state of the motor to the microcontroller unit.

[0015] For the system according to the first aspect of the present invention, the microcontroller samples the amplified pressure signal acquired by the sampling unit to obtain a sampling signal; the target values set by the host computer include a target pressure value, a target preloading position, parameters to be adjusted by the PID algorithm, and a self-learning bias value; the microcontroller calls the PID algorithm, determines a control increment based on the sampling signal and the target values set by the host computer, and determines a control parameter based on the control increment; generates a first control parameter for controlling the motor based on the control parameter, and sends the first control parameter to the control execution unit;

[0016] The host computer is connected to the microcontroller through the USB port of the microcontroller, and the host computer sends the parameters set by the user and the control instructions for remote control to the microcontroller; the parameters set by the user are the target values set by the host computer.

[0017] For the system according to the first aspect of the present invention, the initialization method of the system for adjusting the motor force control accuracy is as follows:

[0018] Configure the pulse parameters of the control execution unit, and the pulse parameters include the pulse type, frequency, width, duty cycle, and phase difference of the motor driver; the control execution unit uses the RS485 Modbus RTU protocol to configure the first RS485 parameters of the control execution unit, and the first RS485 parameters include the baud rate, station ID address, displacement register, return-to-origin register, current position register, disable and enable registers of the motor driver;

[0019] Use the RS485 Modbus RTU protocol to configure the second RS485 parameters of the second sampling unit, and the second RS485 parameters include the baud rate, station ID address, current pressure value register, pressure value clearing register, and sampling rate output register of the pressure amplifier;

[0020] The host computer configures the preset parameters of the PID algorithm, and the preset parameters of the PID algorithm include the preset value of the P proportionality coefficient, the preset value of the I integral coefficient, and the preset value of the D differential coefficient.

[0021] Preferably, the PID algorithm is:

[0022]

[0023] Wherein, is the control increment, k is the current iteration number, is the error corresponding to the kth iteration, is the error corresponding to the (k - 1)th iteration, is the error corresponding to the (k - 2)th iteration, , , All are parameters that need to be adjusted by the PID algorithm. is the P proportionality coefficient, is the I integral coefficient, is the D proportionality coefficient; , is the target pressure value, is the pressure sensor value obtained by the pressure amplifier.

[0024] The second aspect of the present invention proposes a method for adjusting the force control accuracy of a motor. Based on the system for adjusting the force control accuracy of a motor as described above, the method includes:

[0025] The user uses the host computer to issue a force control instruction, and the system for adjusting the force control accuracy of the motor drives the motor to adjust the rotation speed, rotation direction and current position of the motor so that the pressure applied to the device under test reaches the target pressure value;

[0026] Obtain the force control test data of the device under test.

[0027] A computer-readable storage medium provided by the present invention stores multiple instructions; the multiple instructions are used to be loaded and executed by a processor to perform the method as described in the first aspect of the present invention.

[0028] An electronic device provided by the present invention is characterized in that the electronic device includes:

[0029] A processor for executing multiple instructions;

[0030] A memory for storing multiple instructions;

[0031] Among them, the multiple instructions are used to be stored by the memory and loaded and executed by the processor to perform the method as described in the first aspect of the present invention.

[0032] The beneficial technical effects brought by the present invention include:

[0033] (1) The present invention realizes the adaptation and compatibility of motors supporting pulse and RS485 communication protocols and pressure amplifiers with analog interfaces, thus greatly broadening the user's selection range and reducing the inconvenience and cost burden caused by manufacturer restrictions;

[0034] (2) The present invention not only supports standard pulse and 485 communication interfaces, but also provides rich interface resources, which greatly facilitates the user's secondary development and customization requirements. While ensuring high performance, the present invention realizes cost control and provides a high-cost performance force control solution for users.

[0035] (3) The present invention adopts the PID algorithm. Through precise algorithm tuning and in cooperation with the hardware design, it ensures that the force control stability accuracy can reach + / -0.01N of the target value, providing strong technical support for application scenarios that require high-precision force control, such as precision manufacturing, automated assembly lines, experimental equipment, etc. Description of the Drawings

[0036] Figure 1 It is a test schematic diagram of the system for adjusting the motor force control accuracy according to the present invention.

[0037] Figure 2 It is a structural schematic diagram of the system for adjusting the motor force control accuracy according to the present invention. Detailed Embodiments

[0038] The present invention will be described in detail below with reference to the drawings and embodiments.

[0039] As Figure 1 shown, the present invention proposes a system for adjusting the motor force control accuracy, including:

[0040] A pressure amplifier, a pressure sensor, a motor, a motor driver, and a force control subsystem;

[0041] The pressure sensor is deployed on the device to be measured. After the system for adjusting the motor force control accuracy finishes the pre-pressure position self-learning, it senses the pressure applied on the device to be measured. The pressure amplifier amplifies the pressure signal obtained by the pressure sensor, and the amplified pressure signal is input into the force control subsystem. The force control subsystem determines the first control parameter for controlling the motor according to the amplified pressure signal, and sends the first control parameter to the control execution unit. The control execution unit controls the motor driver to drive the motor, adjusting the rotation speed, rotation direction and the current position of the motor, so that the pressure applied on the device to be measured reaches the target pressure value;

[0042] The force control subsystem includes a host computer, a sampling unit, a micro-control unit and a control execution unit;

[0043] The micro-control unit obtains the sampling signal and the target value set by the host computer, calls the PID algorithm to output the control parameter, generates the first control parameter for controlling the motor based on the control parameter, and the control execution unit drives the motor based on the first control parameter. The sampling signal is obtained based on the amplified pressure signal acquired by the sampling unit.

[0044] Further, the control execution unit includes a plurality of pulse interfaces and a first RS485 communication interface. The motor is connected to one of the plurality of pulse interfaces or to the first RS485 communication interface. The control execution unit controls the motor driver to drive the motor based on the first control parameter and feeds back the current state of the motor to the micro control unit.

[0045] The sampling unit includes a first sampling unit and a second sampling unit. The sampling speed of the first sampling unit is greater than that of the second sampling unit. The first sampling unit and the second sampling unit are alternatively used. The first sampling unit has multiple analog quantity acquisition interfaces, and the second sampling unit has a second RS485 communication interface. When the first sampling unit is selected, the pressure amplifier is connected to one of the multiple analog quantity acquisition interfaces. When the second sampling unit is selected, the pressure amplifier is connected to the second RS485 communication interface. The sampling unit adjusts the sampling frequency based on the control instruction of the micro control unit.

[0046] The micro control unit samples the amplified pressure signal obtained by the sampling unit to obtain a sampling signal. The target values set by the host computer include a target pressure value, a target pre-pressing position, parameters to be adjusted by the PID algorithm, and a self-learning offset value. The micro control unit calls the PID algorithm, determines a control increment based on the sampling signal and the target values set by the host computer, and determines a control parameter based on the control increment. A first control parameter for controlling the motor is generated based on the control parameter and sent to the control execution unit.

[0047] The host computer is connected to the micro control unit through the USB port of the micro control unit. The host computer sends the parameters set by the user and the control instructions for remote use to the micro control unit. The parameters set by the user are the target values set by the host computer.

[0048] Further, the system for adjusting the force control precision of the motor supports the coordinated control of multiple motors. During the coordinated control of multiple motors, each pulse interface of the control execution unit can be connected to one motor for motor force control. The first RS485 communication interface can expand multiple connection paths, and each connection path is used to connect a motor for motor force control or other motor control.

[0049] Furthermore, the first sampling unit and the second sampling unit support the collaborative use of multiple pressure amplifiers; when multiple pressure amplifiers are used collaboratively, each analog interface of the first sampling unit can be connected to a pressure amplifier to amplify the pressure; the second RS485 communication interface of the second sampling unit can expand multiple connection paths, and each connection path is used to connect a pressure amplifier to amplify the pressure. The purpose of setting this sampling unit in the present invention is to select a specific sampling unit according to actual usage needs, and both sampling units provide multiple expansion interfaces in design to realize the use and expansion of multiple pressure amplifiers, so as to realize the amplification of small-value pressure and high-precision pressure.

[0050] In this embodiment, the control execution unit provides multiple pulse interfaces and a first RS485 communication interface, enabling adaptation to a variety of motors. Users can select the connection method according to actual needs, ensuring the diversity and wide adaptability of the motor control method, and meeting the scenarios of single-channel and multi-channel motor pulse control used by users. The number of pulse interfaces is 4, which can support force control of 4 motors simultaneously. The first RS485 communication interface supports the expansion of up to 4 motors for force control. In non-force control scenarios, the pulse interfaces can also support the conventional control of 4 motors, and the first RS48 communication interface supports the expansion of up to 32 motors for conventional control.

[0051] The first sampling unit and the second sampling unit also enable users to freely select the interfaces of the pressure amplifiers according to actual needs and application scenarios, ensuring the diversity and wide adaptability of the pressure amplifier control method. For example, the first sampling unit supports the acquisition of analog outputs of 4 pressure amplifiers (2-channel differential or 4-channel pseudo-differential input), meeting the scenarios of single-channel and multi-channel with high sampling rate requirements used by users;

[0052] The second RS485 communication interface of the second sampling unit supports the expansion of up to 4 pressure amplifiers for access in force control scenarios, and supports the expansion of up to 32 accesses in non-force control scenarios.

[0053] The pressure amplifier is calibrated before use. The calibration method of the pressure amplifier is as follows:

[0054] Select a pressure sensor based on the test requirements. The total range of the pressure sensor should be greater than or equal to 2 times the maximum pressure expected to be applied by the device under test;

[0055] Calibrate the pressure sensor using a standard weight.

[0056] The initialization method of the system for adjusting the force control accuracy of the motor is as follows:

[0057] Configure the pulse parameters of the control execution unit, where the pulse parameters include the pulse type, frequency, width, duty cycle, and phase difference of the motor driver; the control execution unit uses the RS485 Modbus RTU protocol to configure the first RS485 parameters of the control execution unit, and the first RS485 parameters include the baud rate, station ID address, displacement register, return-to-origin register, current position register, disable and enable registers of the motor driver;

[0058] Use the RS485 Modbus RTU protocol to configure the second RS485 parameters of the second sampling unit, and the second RS485 parameters include the baud rate, station ID address, current pressure value register, pressure value zeroing register, sampling rate output register of the pressure amplifier;

[0059] Configure the preset parameters of the PID algorithm in the host computer, and the preset parameters of the PID algorithm include the preset value of the P proportionality coefficient, the preset value of the I integral coefficient, and the preset value of the D differential coefficient.

[0060] After the system for adjusting the force control accuracy of the motor is initialized, the motor performs pre-pressure position self-learning. The pre-pressure position is the contact position between the indenter of the mechanism connected to the motor and the device to be tested. The purpose of the pre-pressure position self-learning is to enable the system for adjusting the force control accuracy of the motor to obtain and save the pre-pressure position. Before the force control process, the system for adjusting the force control accuracy of the motor first calls the pre-pressure position to make the motor connect the indenter to quickly reach the pre-pressure position of the device to be tested, and then enters the force control process to improve the execution efficiency of the entire action cycle.

[0061] The method of the pre-pressure position self-learning is as follows:

[0062] The host computer sends the self-learning offset value set by the user to the micro-control unit, and then sends the pre-pressure position self-learning instruction. The system for adjusting the force control accuracy of the motor controls the motor to start running and real-time obtains the value of the pressure amplifier. When it is detected that the value of the pressure amplifier is equal to or greater than 1N, it is determined that the indenter of the mechanism connected to the motor has contacted the device to be tested, and the motor is adjusted for a position with a deviation less than the preset threshold. The preset threshold is 1N; after the system for adjusting the force control accuracy of the motor continuously determines that the value of the pressure amplifier is within the preset threshold for 10 times, subtract the self-learning offset value from the position value corresponding to the current position of the motor as the pre-pressure position value, and use the position corresponding to the pre-pressure position value as the pre-pressure position. The self-learning mechanism of the present invention is carried out through the self-learning offset value set by the host computer. The above method of pre-pressure position self-learning can achieve high-precision pressure regulation, so that the continuous acting force of the actuator on the test device reaches the accuracy of + / -0.01N of the target value.

[0063] In the present invention, after the self-learning of the preloading position is completed, when the system for adjusting the force control precision of the motor is used subsequently, the preloading position can be directly obtained without repeating the learning of the preloading position.

[0064] The PID algorithm is as follows:

[0065]

[0066] Wherein, is the control increment, k is the current iteration number, is the error corresponding to the kth iteration, is the error corresponding to the (k - 1)th iteration, is the error corresponding to the (k - 2)th iteration, , , are all parameters that need to be adjusted in the PID algorithm, is the P proportionality coefficient, is the I integral coefficient, is the D proportionality coefficient; , is the target pressure value, is the pressure sensor value obtained by the pressure amplifier.

[0067] In the present invention, the micro control unit sends the control increment to the control execution unit to adjust the current position of the motor so that the pressure value acting on the device under test approaches .

[0068] The present invention also provides a method for adjusting the force control precision of the motor. Based on the system for adjusting the force control precision of the motor as described above, the method includes:

[0069] The user uses the host computer to issue a force control instruction, and the system for adjusting the force control precision of the motor drives the motor to adjust the rotation speed, rotation direction and current position of the motor so that the pressure applied to the device under test reaches the target pressure value;

[0070] Obtain the force control test data of the device under test.

[0071] The above specific embodiments only describe the design principle of the present invention. The shapes and names of the components in this description can be different and are not limited. Therefore, those skilled in the art of the present invention can modify or equivalently replace the technical solutions recorded in the foregoing embodiments; and these modifications and replacements do not depart from the spirit and technical solutions of the present invention, and shall all fall within the protection scope of the present invention.

Claims

1. A system for adjusting the force control accuracy of a motor, characterized in that: The system includes: Pressure amplifier, pressure sensor, motor, motor driver, force control subsystem; The force control subsystem includes a host computer, a sampling unit, a microcontroller unit and a control execution unit; The pressure sensor is deployed on the device under test, and after the system for adjusting the motor force control accuracy performs the pre-pressure position self-learning, the pressure applied to the device under test is sensed; the pressure amplifier amplifies the pressure signal obtained by the pressure sensor, and the amplified pressure signal is input into the force control subsystem; the force control subsystem determines the first control parameter of the control motor according to the amplified pressure signal, and sends the first control parameter to the control execution unit, and the control execution unit controls the motor driver to drive the motor, adjusts the motor speed, rotation direction and current position of the motor, so that the pressure applied to the device under test reaches the target pressure value; The microcontroller unit obtains the sampling signal and the target value set by the host computer, and calls the PID algorithm to output the control parameter; based on the control parameter, a first control parameter for controlling the motor is generated, and the control execution unit drives the motor based on the first control parameter; the sampling signal is obtained based on the amplified pressure signal obtained by the sampling unit; The sampling unit includes a first sampling unit and a second sampling unit, the sampling speed of the first sampling unit is greater than the sampling speed of the second sampling unit; the first sampling unit and the second sampling unit are used selectively, the first sampling unit has a multi-channel analog quantity acquisition interface, and the second sampling unit has a second RS485 communication interface; the sampling unit adjusts the sampling frequency based on the control instruction of the micro control unit; The first sampling unit and the second sampling unit support the coordinated use of multiple pressure amplifiers; when multiple pressure amplifiers are used in coordination, each analog interface of the first sampling unit can be connected to one pressure amplifier for amplifying pressure; the second RS485 communication interface of the second sampling unit can expand multiple connection paths, each connection path is used to connect a pressure amplifier for amplifying pressure.

2. The system according to claim 1, characterized in that After the system for adjusting the motor force control accuracy is initialized, the motor performs preload position self-learning, and the preload position self-learning method is: The host computer sends a self-learning bias value set by the user to the microcontroller unit, and then sends a pre-stress position self-learning instruction. The system for adjusting the motor force control accuracy controls the motor to start running, and obtains the value of the pressure amplifier in real time. When it is detected that the value of the pressure amplifier is equal to or greater than 1N, it is determined that the pressure head of the mechanism connected to the motor has contacted the device to be tested, and the motor is adjusted to a position with a deviation less than a preset threshold, and the preset threshold is 1N; after the system for adjusting the motor force control accuracy determines that the value of the pressure amplifier is within the preset threshold for 10 consecutive times, the position value corresponding to the current position of the motor minus the self-learning bias value is used as the pre-stress position value, and the position corresponding to the pre-stress position value is used as the pre-stress position.

3. The system according to claim 1, characterized in that The control execution unit includes multiple pulse interfaces and a first RS485 communication interface, and the motor is connected to one of the multiple pulse interfaces or to the first RS485 communication interface; the control execution unit controls the motor driver to drive the motor based on the first control parameter, and feeds back the current state of the motor to the micro control unit.

4. The system according to claim 1, characterized in that The microcontroller unit samples the amplified pressure signal obtained by the sampling unit to obtain a sampling signal; the target value set by the host computer includes a target pressure value, a target pre-pressure position, parameters that need to be adjusted by the PID algorithm, and a self-learning bias value; the microcontroller unit calls the PID algorithm, and determines a control increment based on the sampling signal and the target value set by the host computer, and determines a control parameter based on the control increment; generates a first control parameter for controlling the motor based on the control parameter, and sends the first control parameter to the control execution unit; The host computer is connected to the micro control unit via the USB port of the micro control unit, and the host computer sends the parameters set by the user and the remote control instructions to the micro control unit; the parameters set by the user are the target values ​​set by the host computer.

5. The system according to claim 1, wherein: The initialization method of the system for adjusting the motor force control accuracy is: The pulse parameters of the control execution unit are configured, and the pulse parameters include the pulse type, frequency, width, duty cycle and phase difference of the motor driver; the control execution unit uses the RS485 Modbus RTU protocol to configure the first RS485 parameter of the control execution unit, and the first RS485 parameter includes the baud rate, site ID address, displacement register, return register, current position register, disable and enable register of the motor driver; Using the RS485 Modbus RTU protocol, configure the second RS485 parameters of the second sampling unit, wherein the second RS485 parameters include the baud rate of the pressure amplifier, the site ID address, the current pressure value register, the pressure value reset register, and the sampling rate output register; The PID algorithm preset parameters are configured in the host computer, and the PID algorithm preset parameters include a P proportional coefficient preset value, an I integral coefficient preset value, and a D differential coefficient preset value.

6. The system according to any one of claims 1 to 5, characterized in that: The PID algorithm is: in, To control the increment, k is the current number of iterations, is the error corresponding to k iterations, is the error corresponding to k-1 iterations, is the error corresponding to k-2 iterations, , , These are the parameters that need to be adjusted by the PID algorithm. is the P proportionality coefficient, is the I integral coefficient, is the D proportionality coefficient; , is the target pressure value, The pressure sensor value obtained for the pressure amplifier.

7. A method for adjusting the force control accuracy of a motor, based on a system for adjusting the force control accuracy of a motor as claimed in any one of claims 1 to 6, characterized in that: The method comprises: The user uses the host computer to issue a force control instruction, and the system for adjusting the motor force control accuracy drives the motor, adjusts the motor speed, rotation direction and current position of the motor, so that the pressure applied to the device under test reaches the target pressure value; Obtain force control test data of the device under test.

8. A computer-readable storage medium, characterized in that: The storage medium stores a plurality of instructions; the plurality of instructions are used for the processor to load and execute the method as claimed in claim 7.

9. An electronic device, characterized in that: The electronic device comprises: A processor, which is used to execute multiple instructions; A memory for storing a plurality of instructions; Wherein, the multiple instructions are used to be stored by the memory, and loaded and executed by the processor as described in claim 7.

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