Sample tube rotating gripper control system and sample tube cap opening device

Abstract

The utility model discloses a sample tube rotary jaw control system and sample pipe switch cover device adopt the curve control algorithm function of built -in of jaw MCU control chip to send information to FOC module, and FOC module controls FOC drive chip drive first MOS tube circuit through PWM pulse and completes the motion control to the clamping motor to the utility model discloses the mature FOC algorithm chip on the market, utilizes FOC closed loop control algorithm to realize the accurate control to the jaw clamping force, position, speed, greatly improved the control precision of jaw, reduced the development difficulty of sample tube rotary jaw control system.

Description

Technical Field

[0001] This utility model relates to the field of gripper control technology, and is particularly applicable to sample tube rotating gripper control system and sample tube opening and closing device. Background Technology

[0002] Medical equipment needs to automatically open and transport sample tubes containing bodily fluids, which involves clamping and rotating the sample tubes. Electric grippers can effectively solve this problem.

[0003] Currently, traditional electric gripper control systems use a pure current-based approach, with the gripper's MCU control chip connected to a driver chip, which in turn is connected to a MOS circuit. A PWM pulse is sent to the driver chip, which converts the PWM pulse into a signal to control the MOS circuit, thereby controlling the motor's movement. However, this method cannot precisely control the gripping speed, nor can it achieve accurate coordination of gripping position, speed, and gripping force, and its control precision is low. Summary of the Invention

[0004] The purpose of this invention is to provide a sample tube rotating gripper control system and a sample tube opening and closing device to solve the problems of current electric grippers being unable to accurately control the gripping speed, unable to achieve precise coordination of gripping position, speed, and gripping force, and having low control accuracy.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The sample tube rotating gripper control system of this utility model includes a gripper MCU control chip, an FOC module, a first MOS transistor circuit, a gripping motor, a stepper control chip, a second MOS transistor circuit, and a rotating motor; The gripper MCU control chip is communicatively connected to the FOC module and the stepper control chip respectively; the gripping motor is equipped with a first motor encoder; the signal output terminal of the first motor encoder is communicatively connected to the FOC module, and the FOC module drives the first MOS transistor circuit according to the control signal of the gripper MCU control chip and the signal of the first motor encoder to control the movement of the gripper motor; the stepper control chip drives the second MOS transistor circuit according to the control signal of the gripper MCU control chip to control the movement of the rotary motor.

[0006] Preferably, the FOC module includes an FOC algorithm chip and an FOC driver chip, wherein the FOC algorithm chip and the gripper MCU control chip control the FOC driver chip through PWM pulses; and the FOC driver chip drives the first MOS transistor circuit.

[0007] Preferably, the FOC module is an FOC chip, which integrates an FOC algorithm module and an FOC driver module.

[0008] Preferably, the rotary motor is equipped with a second motor encoder; the signal output terminal of the second motor encoder is connected to the signal input terminal of the stepper control chip.

[0009] Preferably, the first motor encoder and the second motor encoder are differential or single-ended.

[0010] Preferably, the first motor encoder and the second motor encoder are differential type, and the differential signal is converted into a single-ended signal by a differential-to-single-ended chip and input to the FOC module and the stepper control chip.

[0011] Preferably, the output current sampling signal of the first MOS transistor circuit is amplified by the operational amplifier circuit and then connected to the signal input terminal of the FOC module; the operational amplifier circuit is independent of the FOC module or integrated with the FOC module.

[0012] Preferably, the output current sampling signal of the second MOS transistor circuit is connected to the signal input terminal of the stepper control chip.

[0013] Preferably, the first motor encoder and the second motor encoder are magnetic encoders, optical encoders, Hall sensors, or the back electromotive force signal of the motor.

[0014] Preferably, the gripper MCU control chip or the FOC module includes a curve control algorithm function for planning the gripper motion curve.

[0015] This utility model also provides a sample tube opening and closing device, including a gripper and a sample tube rotating gripper control system. The clamping motor is located at the output end of the rotating motor, and the gripper is located at the output end of the clamping motor. The sample tube rotating gripper control system controls the rotating motor and the clamping motor to move so that the gripper can open or close the sample tube.

[0016] The advantage of this invention is that it uses a mature FOC module available on the market and utilizes the FOC closed-loop control algorithm to achieve precise control of the gripper's clamping force, position, and speed, thereby reducing the development difficulty of the sample tube rotating gripper control system. Attached Figure Description

[0017] Figure 1 This is a diagram of the sample tube rotating gripper control system of this utility model. Detailed Implementation

[0018] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] The sample tube rotating gripper control system of this utility model includes a gripper MCU control chip, an FOC module, a first MOS transistor circuit, a gripping motor, a stepper control chip, a second MOS transistor circuit, and a rotating motor.

[0020] The gripper MCU control chip is a commercially available control chip capable of communication protocol conversion, and it has a built-in curve control algorithm function for planning the gripper's motion curve. The gripper MCU control chip connects the overall control unit (including the gripper) with the FOC module and stepper control chip via pass-through, enabling parameter setting and querying between the overall control unit, FOC module, and stepper control chip. The overall control unit is the control center of the entire device using the sample tube rotating gripper control system described in this invention. In this device, gripper control is only one part. The sample tube rotating gripper control system described in this invention is a subsystem that works in conjunction with the entire device to complete the gripper control.

[0021] like Figure 1 As shown, the overall machine control unit communicates with the gripper MCU control chip via a communication interface. The gripper MCU control chip communicates with the FOC module and the stepper control chip, respectively, through SPI communication, RS485 communication, etc. Communication between the gripper MCU control chip and the FOC module and the stepper control chip is achieved through the chip select mode of SPI communication or the address of RS485 communication, thereby realizing the control of the gripping motor and the rotary motor.

[0022] The FOC module drives the first MOS transistor circuit based on the control signals from the gripper MCU control chip and the first motor encoder, thereby controlling the movement of the gripper motor. Specifically, the FOC module includes an FOC algorithm chip and an FOC driver chip. The FOC algorithm chip uses a mature chip incorporating an FOC closed-loop control algorithm. It outputs PWM pulse signals based on the control signals from the gripper MCU control chip and the first motor encoder, and sends these signals to the FOC driver chip. The FOC driver chip uses a mature chip that converts the PWM signals into motor drive signals to drive the gripper motor. The output of the FOC driver chip is converted by the first MOS transistor circuit and then input to the gripper motor to achieve motion control of the gripper motor. The first motor encoder is mounted on the gripper motor, and its signal output terminal is connected to the signal input terminal of the FOC algorithm chip to provide the FOC algorithm chip with motor position information. In other embodiments, the FOC module can also be a single FOC chip that integrates the algorithm and driver modules; that is, the FC chip essentially integrates the FOC algorithm chip and the FOC driver chip into a single chip.

[0023] The stepper control chip also uses a commercially available mature chip that integrates stepper motor control algorithms and drivers. The second MOS transistor circuit is driven by the control signal of the gripper MCU control chip to control the movement of the rotary motor.

[0024] The working process of this utility model is as follows: When the machine is powered on, the control unit presets the parameters of the gripper. The preset parameters include, but are not limited to: maximum speed, maximum acceleration, maximum current, maximum position, rated current, parameter limit value, encoder resolution, encoder direction, operational amplifier gain, and all other preset operating parameters used for chip settings, parameter initialization, operation, and standby.

[0025] Depending on the equipment's needs, the overall control unit can send commands such as clamping, rotating, clamping-rotating combination, stopping, initializing, and resetting to control the operation of the grippers. The commands sent by the overall control unit include a set of control parameters for the grippers, such as the gripper's operating speed, acceleration, and torque (or current) value.

[0026] When the sample tube rotating gripper control system of this utility model receives parameterized control commands such as clamping, rotating, clamping-rotating combination, stopping, initializing, and resetting from the whole machine control unit, the gripper MCU control chip sends information to the FOC module according to its built-in curve control algorithm function. Based on the built-in algorithm of commercially available gripper MCU control chips, in speed mode, the gripper MCU control chip calculates the speed every 1ms and sends the calculation result to the FOC module to adjust the speed during motor acceleration and deceleration. In position mode, the gripper MCU control chip calculates the position information every 1ms and sends the calculation result to the FOC module to control the motor speed.

[0027] The built-in curve control algorithm functions of the gripper MCU control chip include T-curve control algorithm functions, S-curve control algorithm functions, and multi-point curve control algorithm functions.

[0028] Taking the T-curve control algorithm function as an example, the gripper MCU control chip, based on the control mode and speed mode in the received set of parameters, subdivides the T-curve speed according to the preset speed and acceleration in the received set of parameters, calculates the speed information every 1ms (which can be changed in specific use), and sends the calculation result to the FOC module. The FOC algorithm chip in the FOC module has a built-in closed-loop control algorithm that controls the motor acceleration by matching the position information with the movement position every ms, realizing the adjustment of the motor speed during acceleration and deceleration phases using T-curve control.

[0029] In position mode, the gripper MCU control chip calculates the position information every 1ms (this can be changed for specific applications) and sends the result to the FOC module. The FOC algorithm chip in the FOC module uses its built-in closed-loop control algorithm to control the motor speed by matching the position information with the movement position every ms, achieving T-shaped curve control of the motor speed. The position information is obtained through the first motor encoder installed on the gripping motor.

[0030] Subsequently, the FOC algorithm chip outputs a PWM pulse signal, which is sent to the FOC driver chip. The FOC driver chip converts the PWM signal into a motor drive signal to drive the clamping motor, which is then converted into an electrical signal to control the movement of the clamping motor via the first MOS transistor circuit.

[0031] In some embodiments, to balance cost, control accuracy, and device size, the clamping motor in this invention can be a servo motor; the rotary motor can be a stepper motor. A second motor encoder can also be installed on the rotary motor in this invention, connecting its signal output to the signal input of the stepper control chip for real-time monitoring of the rotary motor's position. The first and second motor encoders can be differential or single-ended. When a differential motor encoder is selected, a differential-to-single-ended chip is needed to convert the differential signal into a single-ended signal for input to the FOC module and the stepper control chip. Optional motor encoders include magnetic encoders, optical encoders, Hall sensors, or the motor's back EMF signal, etc.

[0032] In other embodiments, the output currents of the first MOSFET circuit and the second MOSFET circuit can be sampled. The sampled signal of the output current of the first MOSFET circuit can be amplified by an operational amplifier circuit and then connected to the signal input terminal of the FOC module. Depending on the actual needs, the operational amplifier circuit can be directly integrated with the FOC module, or a separate operational amplifier circuit can be selected. The sampled signal of the output current of the second MOSFET circuit can be directly connected to the signal input terminal of the stepper control chip.

[0033] In other embodiments, the curve control algorithm function for planning the gripper's motion curve can also be built into the FOC module, i.e., a chip with both curve control algorithm function and FOC closed-loop control algorithm is selected. The FOC module can also be an MCU that already includes the FOC closed-loop control algorithm. Currently, commercially available FOC modules with built-in curve control algorithm functions generally use multi-point motion curve functions. In this case, the gripper MCU control chip in this invention only needs to send the speed, acceleration, and position information of each motion stage to the FOC module, and the FOC module can accurately control the motor motion based on the built-in multi-point motion curve function.

[0034] The above-mentioned method of using the FOC module to control the movement of the clamping motor can also be directly applied to the control of rotating motors. That is, to find a mature stepper control chip that includes the FOC closed-loop control algorithm, so as to use the existing FOC algorithm to achieve precise control of the rotating motor in the current loop, speed loop and position loop.

[0035] The following is a detailed description of the operation and control process of the sample tube rotating gripper control system described in this invention, specifically addressing the reset process of the gripper action commanded by the overall machine control unit: The machine control unit issues a gripper reset command, carrying relevant control parameters. The gripper MCU control chip sends the control parameters and command to the FOC algorithm chip of the FOC module. The FOC algorithm chip outputs a PWM signal to the FOC driver chip, which converts the PWM signal into a motor drive signal to drive the gripper motor. This signal is then converted into an electrical signal to control the gripper motor's movement via the first MOS transistor circuit. Simultaneously, the FOC algorithm chip receives the first motor encoder signal and the output current sampling signal from the first MOS transistor circuit. Using its built-in FOC closed-loop control algorithm, the FOC algorithm chip compares the deviation between the gripper motor's speed and the target speed in the control parameters, and the deviation between the output current sampling signal and the target current in the control parameters, respectively, and determines the relationship between these deviations and the corresponding allowable deviations in the control parameters, thus controlling the gripper motor to stop. Finally, the FOC algorithm chip receives the first motor encoder signal to obtain the gripper's current position and compares it with the target position in the control parameters. When the difference between the two positions is less than or equal to the allowable position deviation, it indicates that the machine control unit has successfully issued the gripper reset command. Specific parameter values ​​can be set according to user requirements.

[0036] In addition, this utility model also provides a sample tube opening and closing device, which includes a gripper and the aforementioned sample tube rotating gripper control system. The gripping motor is located at the output end of the rotating motor, the gripper is located at the output end of the gripping motor, and the sample tube rotating gripper control system controls the movement of the rotating motor and the gripping motor to enable the gripper to open or close the sample tube.

[0037] Because the sample tube rotating gripper control system of this utility model uses a mature FOC algorithm chip to achieve precise control of the gripper's clamping force, position, and speed, it also improves the accuracy of opening or closing the sample tube cap.

Claims

1. A sample tube rotating gripper control system, characterized in that: It includes a gripper MCU control chip, an FOC module, a first MOSFET circuit, a gripping motor, a stepper control chip, a second MOSFET circuit, and a rotary motor; The gripper MCU control chip is communicatively connected to the FOC module and the stepper control chip respectively; the gripping motor is equipped with a first motor encoder; the signal output terminal of the first motor encoder is communicatively connected to the FOC module, and the FOC module drives the first MOS transistor circuit according to the control signal of the gripper MCU control chip and the signal of the first motor encoder to control the movement of the gripper motor; the stepper control chip drives the second MOS transistor circuit according to the control signal of the gripper MCU control chip to control the movement of the rotary motor.

2. The sample tube rotating gripper control system according to claim 1, characterized in that: The FOC module includes an FOC algorithm chip and an FOC driver chip. The FOC algorithm chip and the gripper MCU control chip control the FOC driver chip through PWM pulses. The FOC driver chip drives the first MOS transistor circuit.

3. The sample tube rotating gripper control system according to claim 1, characterized in that: The FOC module is an FOC chip, which integrates an FOC algorithm module and an FOC driver module.

4. The sample tube rotating gripper control system according to claim 1, characterized in that: The rotary motor is equipped with a second motor encoder; the signal output terminal of the second motor encoder is connected to the signal input terminal of the stepper control chip.

5. A sample tube rotating gripper control system according to claim 4, characterized in that: The first motor encoder and the second motor encoder are differential or single-ended.

6. A sample tube rotating gripper control system according to claim 4, characterized in that: The first motor encoder and the second motor encoder are differential type. The differential signal is converted into a single-ended signal by a differential-to-single-ended chip and input to the FOC module and the stepper control chip.

7. The sample tube rotating gripper control system according to claim 1, characterized in that: The output current sampling signal of the first MOS transistor circuit is amplified by the operational amplifier circuit and then connected to the signal input terminal of the FOC module; the operational amplifier circuit is independent of the FOC module or integrated with the FOC module.

8. The sample tube rotating gripper control system according to claim 1, characterized in that: The output current sampling signal of the second MOS transistor circuit is connected to the signal input terminal of the stepper control chip.

9. A sample tube rotating gripper control system according to claim 4, characterized in that: The first motor encoder and the second motor encoder are magnetic encoders, optical encoders, Hall sensors, or back EMF signals of the motor.

10. A sample tube rotating gripper control system according to claim 4, characterized in that: The gripper MCU control chip or the FOC module contains a curve control algorithm function for planning the gripper motion curve.

11. A sample tube opening and closing device, comprising a gripper and a sample tube rotating gripper control system as described in any one of claims 1-10, characterized in that: The clamping motor is located at the output end of the rotary motor, and the gripper is located at the output end of the clamping motor. The sample tube rotation gripper control system controls the rotary motor and the clamping motor to move so that the gripper can open or close the sample tube.

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