Motor control measuring circuit based on STM32ARM processor and universal Ethernet interface

Abstract

The invention discloses a motor control measuring circuit based on an STM32ARM processor and a universal Ethernet interface. A minimum system with a 32-bit ARM processor of an STM32 single-chip microcomputer as a core is used as a basic circuit, an Ethernet communication module, a multi-path DI isolation input channel, a DO output and drive circuit and an angular displacement analog quantity acquisition circuit are expanded, an on-chip program of a main control chip is used as lower computer software, and communication with upper computer software is carried out through a user-defined Ethernet UDP protocol. The upper computer and the lower computer cooperate with each other to complete the functions of control instruction sending, motor state parameter acquisition, abnormal fault isolation protection and the like. The high operation speed and abundant interface resources of the STM32 single-chip microcomputer are utilized to complete the intelligent control of the front-end control equipment, so as to achieve the design requirements of high speed, high precision, high reliability and low cost of the system.

Description

Technical Field

[0001] The invention belongs to the field of control and measurement circuit design, and in particular relates to a motor control and measurement circuit based on an STM32ARM processor and a universal Ethernet interface. Background Art

[0002] At present, there are many types of unit test equipment. In the existing technology, most of them are composed of computer host, display, keyboard and mouse, signal adapter box, isolation box, transfer box, cable and other components. The equipment is large in size and has a large number of components. When the tested product undergoes external acceptance tests (vibration, impact, high and low temperature, life, etc.), it is difficult to carry it out, and the equipment is greatly damaged during transportation, and the equipment return rate is high. Due to the different interface protocols of the tested objects, each set of test equipment software is self-contained, and the degree of generalization and productization is low. Therefore, users cannot freely configure software protocols and processing procedures. Currently available equipment can generally only perform digital bus tests on a certain level of products at the same time, and cannot perform multi-level joint tests. The test is time-consuming and the work efficiency is low.

[0003] The STM32 microcontroller is widely used in industrial control, automotive electronics, smart home appliances, medical electronics and other fields, and has been increasingly used in the military field in recent years. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a motor control measurement circuit based on an STM32ARM processor and a universal Ethernet interface.

[0005] The invention adopts low-cost self-developed motor control and measurement circuit design, takes the minimum system with the 32-bit ARM processor of STM32 as the core as the basic circuit, expands the Ethernet communication module, multi-channel DI isolation input channel, DO output and drive circuit, angular displacement analog acquisition circuit, uses the on-chip program of the main control chip as the lower computer software, communicates with the upper computer software through the custom Ethernet UDP protocol, and the upper and lower computers cooperate to complete the functions of sending control instructions, collecting motor state parameters, abnormal fault isolation protection and the like.

[0006] The motor control and measurement circuit based on the STM32ARM processor and the general Ethernet interface includes a main chip control circuit, an Ethernet expansion interface circuit and a peripheral control circuit; the main chip control circuit is the minimum system circuit of the STM32 microcontroller, which can realize general IO port control, AD acquisition, SPI bus control, serial port control, and II2C bus storage; the Ethernet expansion interface circuit includes an Ethernet chip peripheral circuit and a transformer interface circuit; the peripheral control circuit includes a voltage signal conditioning circuit, a switch quantity isolation input circuit, and a switch quantity output and drive circuit.

[0007] The minimum system circuit of the STM32 microcontroller includes the main chip circuit, clock circuit, power supply circuit, startup circuit, reset circuit, USB to serial port circuit, storage circuit, and JLINK debugging interface circuit. The voltage signal conditioning circuit can achieve high-precision conversion of DISP_AD=1.65+0.165×DISP through the voltage division of resistors R24 and R25, two-stage OP07 op amp 1:1 amplification circuit and 3.3V reference voltage voltage division and summing circuit, and adjust the angular displacement voltage signal input by the cover mechanism to the AD acquisition range of 0~3.3V on the microcontroller chip.

[0008] The switch quantity isolation input circuit includes a photocoupler, a light emitting diode, a light emitting triode, a transient suppression diode and an LED working indicator light. The light emitting diode is an input circuit that converts electrical energy into light energy; the light emitting triode is an output circuit that converts light energy into electrical energy; the photocoupler insulates the light emitting diode and the light emitting triode together to achieve electrical isolation of the two circuits; the transient suppression diode is connected in parallel to the signal input end to protect the photocoupler.

[0009] The switch output and drive circuit includes a Darlington transistor array chip, a solid-state relay, a TVS diode and a DC brushed motor, wherein the output end of the solid-state relay is connected in parallel with a TVS diode, so as to avoid insufficient output current caused by the IO port of the single-chip microcomputer directly driving the solid-state relay.

[0010] The beneficial effects of the present invention are as follows:

[0011] The motor control measurement circuit based on STM32ARM processor and universal Ethernet interface has the characteristics of small size, low cost, strong versatility, rich external interface resources, high speed, high precision and high reliability. In addition to motor testing, it can be applied to automated factories, robot control, sensor interface and data acquisition. It can also be used in electrical and motor system testing and measurement fields such as automotive performance testing and vehicle engine control measurement. It has strong scalability, high reliability, good market application prospects, and high social and economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is the schematic diagram of the main chip control circuit and Ethernet expansion interface circuit;

[0013] Figure 2 It is the schematic diagram of the peripheral circuit;

[0014] Figure 3 It is the schematic diagram of the voltage signal conditioning circuit;

[0015] Figure 4 This is the schematic diagram of the switch quantity isolation input circuit;

[0016] Figure 5It is the schematic diagram of switch output and drive circuit. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0018] The present invention adopts a low-cost self-developed motor control and measurement circuit design, with the minimum system with the 32-bit ARM processor of STM32 as the core as the basic circuit, through the expansion of Ethernet communication module, multi-channel DI isolation input channel, DO output and drive circuit, angular displacement analog acquisition circuit, through the on-chip program of the main control chip as the lower computer software, through the custom Ethernet UDP protocol and the upper computer software to communicate, the upper and lower computers cooperate to complete the transmission of control instructions and the collection of motor state parameters, abnormal fault isolation protection and other functions. Utilizing the higher operating speed and rich interface resources of the STM32 single-chip microcomputer, the intelligent control of the front-end control equipment is completed to achieve the high-speed, high-precision, high-reliability and low-cost design requirements of the system.

[0019] The circuit of the present invention comprises (1) a main chip control circuit and an Ethernet expansion interface circuit; and (2) a peripheral control circuit.

[0020] (1) Main chip control circuit and Ethernet expansion interface circuit.

[0021] The main chip control circuit and Ethernet expansion interface circuit schematic diagram is as follows Figure 1 As shown in the figure, the main chip circuit, clock circuit, power circuit, startup circuit, reset circuit, USB to serial port circuit, storage circuit, and JLINK debugging interface circuit are the minimum system circuits of the STM32F103CBT6 chip, which can complete the functions of general IO port control, AD acquisition, SPI bus control, serial port control, and II2C bus storage of system resources through hardware design and software programming. Figure 1 The upper part is the Ethernet expansion interface circuit, which includes the W5500 Ethernet chip peripheral circuit and the RJ45 transformer interface circuit. The 10M / 100M Ethernet communication function between the main control microcontroller and the host computer can be realized through hardware design and main control software programming.

[0022] (2) Peripheral control circuit.

[0023] Peripheral control circuits such as Figure 2As shown, it includes: -10V~+10V angular displacement signal to 0~3.3V voltage signal conditioning circuit, switch quantity isolation input circuit and switch quantity output and drive circuit:

[0024] a. Voltage signal conditioning circuit

[0025] Voltage signal conditioning circuit such as Figure 3 As shown, through the voltage division of resistors R24 and R25, the two-stage OP07 operational amplifier 1:1 amplification circuit and the 3.3V reference voltage voltage division and summing circuit, the high-precision transformation of DISP_AD=1.65+0.165×DISP is realized, and the angular displacement voltage signal input by the blocking mechanism is conditioned to the AD acquisition range of 0~3.3V on the single-chip microcomputer.

[0026] b. Switch quantity isolation input circuit

[0027] The switch quantity isolation input circuit is suitable for collecting switch quantity signals and inputting 28.5V DC voltage. When the input range is set to 18-28.5VDC, it is considered to be a high level and the switch is in the on state. When the input is lower than 18VDC, it is considered to be a low level and the switch is in the off state.

[0028] In order to avoid interference from electrical characteristics and external environment, the circuit uses the optocoupler TLP521 to achieve an electrical-optical-electrical conversion of the signal, thereby achieving input-output isolation.

[0029] At the same time, LED working indicators are installed to monitor the working status of each channel. Figure 4 As shown:

[0030] The optocoupler TLP521 combines an infrared light-emitting diode and a light-emitting triode insulated from each other. The light-emitting diode is the input circuit, which converts electrical energy into light energy; the light-emitting triode is the output circuit, which converts light energy into electrical energy again, thus achieving electrical isolation of the two circuits. In order to protect the optocoupler and prevent large input voltage mutations, a transient suppression diode is connected in parallel at the signal input end.

[0031] Specifically, when the input range is 18 to 28.5 VDC, it is considered to be a high level. At this time, the optocoupler is turned on, and resistors R35, R36 and the light-emitting diode together form an input loop. The following calculation uses the first channel as the component symbol.

[0032] According to the current of 4-20mA when the optocoupler is turned on, when the maximum input voltage is 28.5V,

[0033] 28.5V / 20mA<R35+R36<28.5V / 4mA, that is: 1.425KΩ<R35+R36<7.125KΩ;

[0034] When the input is lower than 18V, it is considered to be a low level. At this time, the working current of the optocoupler must be lower than 4mA. At this time, the optocoupler is not conducting, and resistors R35, R36 and R37 together form an input circuit. At this time,

[0035] 18V / (R35+R36+R37)<4mA, that is: R35+R36+R37>4.5KΩ, take R1=R2=3KΩ, R3=1KΩ.

[0036] The minimum current of the optocoupler is 4mA. According to the optocoupler's current transfer ratio CTR (Current Transfer Ratio) of 50%, it refers to the percentage of the collector current IC to the light-emitting diode input current IF when the tube voltage drop UCE is large enough. Therefore, the collector current IC = IF*50% = 4mA*50% = 2mA. At the same time, in order to make the phototransistor enter the saturation zone as soon as possible, the pull-up resistor R38 is selected to be 4.7KΩ.

[0037] c. Switching output and driving circuit

[0038] By controlling the general GPIO port of the microcontroller main control chip, the DO signal is output in a push-pull manner, such as Figure 5 In the switch output circuit, DO_1 is the first DO signal, which can control the output channel corresponding to the 7-channel Darlington array chip ULN2003 to conduct, and can provide an output drive current of up to 500mA, thereby controlling the connection of the input end of the JGX-72MA solid-state relay. The output end contact of the solid-state relay can connect the load end of the 28V15A DC brushed motor. DO_2 is a backup channel. By using the ULN2003 driver chip, the output current shortage caused by the direct drive of the solid-state relay by the MCU IO port is avoided. At the same time, the TVS diode is connected in parallel at the output end of the relay to avoid the impact of the surge voltage on the MOS tube at the output end of the relay when the motor stops.

Claims

1. A motor control measurement circuit based on STM32ARM processor and general Ethernet interface, characterized in that: The circuit includes a main chip control circuit, an Ethernet expansion interface circuit and a peripheral control circuit; The main chip control circuit is the minimum system circuit of the STM32 microcontroller, which can realize general IO port control, AD acquisition, SPI bus control, serial port control, and II2C bus storage; the Ethernet expansion interface circuit includes the Ethernet chip peripheral circuit and the transformer interface circuit; the peripheral control circuit includes the voltage signal conditioning circuit, the switch quantity isolation input circuit, and the switch quantity output and drive circuit.

2. A motor control measurement circuit based on an STM32ARM processor and a general Ethernet interface according to claim 1, characterized in that, The minimum system circuit of the STM32 microcontroller includes the main chip circuit, clock circuit, power supply circuit, startup circuit, reset circuit, USB to serial port circuit, storage circuit, and JLINK debugging interface circuit.

3. A motor control measurement circuit based on an STM32ARM processor and a general Ethernet interface according to claim 1-2, characterized in that, The model of the STM32 microcontroller is STM32F103CBT6.

4. A motor control measurement circuit based on an STM32ARM processor and a general Ethernet interface according to claims 1-3, characterized in that, The voltage signal conditioning circuit can achieve high-precision conversion of DISP_AD=1.65+0.165×DISP through voltage division by resistors R24 and R25, two-stage OP07 operational amplifier 1:1 amplification circuit and 3.3V reference voltage voltage division and summing circuit, and condition the angular displacement voltage signal input by the blocking mechanism to an AD acquisition range of 0 to 3.3V on the single-chip microcomputer.

5. A motor control measurement circuit based on an STM32ARM processor and a general Ethernet interface according to claims 1-4, characterized in that, The switch quantity isolation input circuit comprises a photoelectric coupler, a light emitting diode, a light emitting triode, a transient suppression diode and an LED working indicator light.

6. A motor control measurement circuit based on STM32ARM processor and general Ethernet interface according to claim 5, characterized in that, The light emitting diode is an input circuit that converts electrical energy into light energy; the light emitting triode is an output circuit that converts light energy into electrical energy again; the photoelectric coupler combines the light emitting diode and the light emitting triode together in an insulated manner to achieve electrical isolation of the two circuits; a transient suppression diode is connected in parallel to the signal input end to protect the photoelectric coupler.

7. A motor control measurement circuit based on an STM32ARM processor and a general Ethernet interface according to claims 1-6, characterized in that, The switch output and drive circuit comprises a Darlington tube array chip, a solid-state relay, a TVS diode and a DC brushed motor, wherein the output end of the solid-state relay is connected in parallel with a TVS diode.

8. A motor control measurement circuit based on an STM32ARM processor and a general Ethernet interface according to claim 7, characterized in that, This can prevent the microcontroller IO port from directly driving the solid-state relay and causing insufficient output current.

9. A motor control measurement circuit based on an STM32ARM processor and a general Ethernet interface according to claim 7, characterized in that, The Darlington transistor array chip model is ULN2003.

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