Motor control system and electric equipment

Abstract

The utility model provides a motor control system and electric equipment, relates to the technical field of motor control, solves the problem that the motor control system of the electric equipment is unstable and is difficult to realize effective braking, and can detect the rotation direction of a motor during rotation to determine the actual advancing direction, thereby improving the braking efficiency. And the advancing direction on logic control is determined by detecting a direction control signal, so that the slope sliding phenomenon is determined under the condition that the directions are inconsistent, and the motor is timely and effectively braked by driving a limiting switch.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor control, and particularly relates to a motor control system and an electric device. BACKGROUND

[0002] At present, intelligent wheelchairs, electric carts and other electric devices are widely used in the market. Taking the intelligent wheelchair as an example, it is very convenient for people with difficulty in movement. Unlike the traditional hand-push wheelchair, the intelligent wheelchair realizes the running control of the driving wheel (i.e. the wheel driven by the motor to provide power for the device) through the motor and the corresponding motor control system, thereby realizing intelligent travel.

[0003] However, the inventor finds that the motor control system of the intelligent wheelchair in the related art has instability, and the user has risks when using the intelligent wheelchair. For example, when driving on a road section with a slope, if the wheelchair malfunctions at this time, the wheelchair will lose control and then the wheelchair will slide down the slope. Moreover, when such an abnormal situation occurs, the user has difficulty in making a reasonable response in time, and a safety accident is likely to occur. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a motor control system and an electric device, which solves the problem that the motor control system of the electric device has instability and cannot realize effective braking. The present application can timely detect the occurrence of the sliding-down-the-slope phenomenon and effectively brake, and the control response of braking is timely, which helps to improve the safety of the electric device.

[0005] In a first aspect, the present application provides a motor control system, which comprises a master control module, a signal acquisition sensor, a limit driving module and a limit switch.

[0006] The detection input end of the signal acquisition sensor is connected with the motor, and the output end of the signal acquisition sensor is connected with the motor detection end of the master control module. The signal acquisition sensor is used for generating a sensor signal, and the sensor signal is a signal used for representing the real-time rotation direction of the motor.

[0007] The input end of the master control module is used for inputting a direction control signal, and the first output end of the master control module is connected with the input end of the limit driving module. The master control module is used for determining a limit control signal according to the sensor signal and the direction control signal, and outputting the limit control signal to the limit driving module. The direction control signal is a signal used for driving the motor to control the advancing action and the advancing direction of the motor.

[0008] The output end of the limit driving module is connected with one end of the limit switch. The limit driving module is used for driving the limit switch to brake the motor under the condition of receiving the limit control signal.

[0009] The motor control system can determine whether the hill-slip phenomenon occurs through detection of the rotating direction of the motor, so that the motor is braked through driving of the limit switch when the hill-slip phenomenon occurs, the motor is braked, effective braking is completed to realize the anti-hill-slip function, the control response of braking is timely, the system stability is good, and the safety of the electric equipment is improved.

[0010] In an embodiment, the limit driving module comprises a first switch unit, a second switch unit and a controllable limit unit.

[0011] The control end of the first switch unit is connected to the first output end of the master control module, the signal output end of the first switch unit is connected to the control end of the second switch unit, and the first switch unit is used for outputting a conduction signal to the second switch unit in the case of receiving a limit control signal;

[0012] The input end of the second switch unit is connected to a working voltage, the output end of the second switch unit is connected to the input end of the controllable limit unit, and the output end of the controllable limit unit is connected to the limit switch, and the second switch unit is used for transmitting a voltage signal to the controllable limit unit in the case of receiving the conduction signal, and the controllable limit unit is used for providing a limit signal to the limit switch to drive the limit switch to brake the motor.

[0013] Through progressive control between the first switch unit and the second switch unit, the limit driving module provided in the embodiment can sequentially turn on the first switch unit and the second switch unit under the driving of the limit driving signal, and then provide a conduction loop for the controllable limit unit to access the working voltage, so as to realize driving of the limit switch and complete braking of the motor, and the first switch unit and the second switch unit can stably respond to the limit driving signal to avoid the case of mis-driving the limit switch due to voltage fluctuation.

[0014] In an embodiment, the first switch unit comprises a first resistor, a second resistor, a third resistor, a fourth resistor and a first transistor.

[0015] The first end of the first resistor is connected to the first output end of the master control module, the second end of the first resistor is connected to the control end of the first transistor, the first end of the second resistor is connected to the control end of the first transistor, and the second end of the second resistor and the output end of the first transistor are both grounded.

[0016] The first end of the third resistor is connected to the input end of the first transistor, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the working voltage.

[0017] The first switch unit can form a switch circuit with the first transistor and the resistors connected to the respective ends of the first transistor, so as to respond to the limit driving signal, thereby helping the limit driving module to respond to the limit driving signal more quickly, and improving the response speed of the motor control system to the brake control.

[0018] In an embodiment, the second switch unit includes a fifth resistor, a first capacitor, a second transistor, a second capacitor and a sixth resistor.

[0019] The first end of the fifth resistor is connected to the signal output end of the first switch unit, the second end of the fifth resistor is connected to the control end of the second transistor, the input end of the second transistor is connected to the working voltage, the first end of the first capacitor is connected to the input end of the second transistor, and the second end of the first capacitor is connected to the control end of the second transistor.

[0020] The output end of the second transistor is connected to the input end of the controllable limit unit, the first end of the second capacitor is connected to the output end of the second transistor, the second end of the second capacitor is grounded, and the sixth resistor is connected in parallel with the second capacitor.

[0021] By controlling the on or off state of the second transistor, the limit driving module can stably drive the limit switch, so that the motor control system can stably brake the motor, and help to improve the stability of the system.

[0022] In an embodiment, the controllable limit unit includes a normally closed switch, the two ends of the normally closed switch are respectively used as the input end and the output end of the controllable limit unit, and the normally closed switch is used to provide the limit signal to the limit switch when the second switch unit receives the on signal, and stop providing the limit signal to the limit switch when the normally closed switch is turned off.

[0023] By setting the normally closed switch, the motor control system can quickly transmit the limit signal, and also provide the user with the function of quickly resetting, so that the motor control system is more reliable, and helps to improve the user experience.

[0024] In an embodiment, the first switch unit includes a first transistor, and the first transistor is an NPN transistor, and the second transistor of the second switch unit is a PMOS transistor.

[0025] The first switch unit forms a switch circuit through the NPN transistor thereon and the connected resistors, so as to further lower the voltage at the gate end of the PMOS transistor, so that the voltage at the gate end of the PMOS transistor quickly reaches the on voltage, so that the PMOS transistor is turned on more quickly, and helps the limit driving module to respond to the limit driving signal more quickly, thereby improving the response speed of the motor control system to the brake control.

[0026] In an embodiment, the limit driving module comprises a motor driving unit and a mechanical limit unit, an input end of the motor driving unit is connected to a first output end of the master control module, an output end of the motor driving unit is connected to an input end of the mechanical limit unit, and an output end of the mechanical limit unit is used to drive the limit switch; wherein the motor driving unit is used to output a pulse sequence signal to the mechanical limit unit upon receiving a limit control signal, and the mechanical limit unit is used to drive the limit switch upon receiving the pulse sequence signal.

[0027] The limit driving module drives the limit switch through mechanical braking, which can provide a reliable braking mode for the motor control system and help further improve the stability of the system.

[0028] In an embodiment, the motor driving unit comprises four output ends, and the pulse sequence signals output by the four output ends of the motor driving unit are PWM signals, and the mechanical limit unit comprises a limit motor, a first NMOS tube, a second NMOS tube, a third NMOS tube, and a fourth NMOS tube.

[0029] The gate end of the first NMOS tube, the gate end of the second NMOS tube, the gate end of the third NMOS tube, and the gate end of the fourth NMOS tube are respectively connected to the pulse sequence signals output by different output ends of the motor driving unit; the drain end of the first NMOS tube is connected to a working voltage, the source end of the first NMOS tube is connected to the drain end of the third NMOS tube, and the source end of the third NMOS tube is grounded; the drain end of the second NMOS tube is connected to a working voltage, the source end of the second NMOS tube is connected to the drain end of the fourth NMOS tube, and the source end of the fourth NMOS tube is grounded; the power supply end of the limit motor is connected to the source end of the first NMOS tube and the source end of the second NMOS tube, and the limit motor is used to drive the limit switch through a mechanical end in a working state.

[0030] The driving circuit of the limit motor is formed by the NMOS tubes, so that the limit motor can drive the limit switch in a working state, and the limit driving module can realize mechanical driving of the limit switch through the limit motor, which helps to further improve the stability of the system.

[0031] In an embodiment, the motor is a three-phase motor, and the motor control system further comprises a pre-driving module and a three-phase inverter driving module, an input end of the pre-driving module is connected to a second output end of the master control module, an output end of the pre-driving module is connected to an input end of the three-phase inverter driving module, and three output ends of the three-phase inverter driving module are respectively connected to three corresponding different phase driving input ends of the three-phase motor.

[0032] The motor control system realizes driving control of the three-phase motor through the pre-driving module and the three-phase inverter driving module, and when applied to the electric device, can ensure efficient energy conversion and precise motor control, and helps to improve the performance of the electric device.

[0033] In a second aspect, the application further provides an electric device, which comprises the motor control system provided in the first aspect.

[0034] The electric device can automatically realize braking of the motor through the motor control system when the hill-start phenomenon occurs, so as to realize the hill-start prevention function, and the control response of the motor braking is timely, which helps to improve the safety of the electric device. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 a principle block diagram of the motor control system provided in an embodiment of the application;

[0036] Figure 2 a circuit structure schematic diagram of the limit driving module provided in an embodiment of the application;

[0037] Figure 3 a structure schematic diagram of the limit driving module provided in another embodiment of the application;

[0038] Figure 4 a structure schematic diagram of the motor control system provided in an embodiment of the application. DETAILED DESCRIPTION

[0039] The embodiments of the application will be further described in detail below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the embodiments of the application, but not to limit the embodiments of the application. In addition, it should be noted that, in order to facilitate the description, only the parts related to the embodiments of the application are shown in the drawings, and the skilled in the art should be able to think that, as long as the technical features are not contradictory, any combination of technical features can constitute an optional embodiment.

[0040] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of a kind and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects before and after are in an "or" relationship. In the description of the present application, "a plurality of" means two or more, and "several" means one or more.

[0041] Electric devices such as intelligent wheelchairs, electric carts, etc. are driven by electric motors to rotate the driving wheels in the device, thereby realizing the movement of the electric device. However, the motor control system of the electric device is unstable, and it is difficult to effectively brake when a fault occurs. For example, taking an intelligent wheelchair as an example, the intelligent wheelchair realizes the operation control of the driving wheel through the motor and the corresponding motor control system, thereby realizing intelligent travel. However, the inventors have found that for people with difficulty in movement, there is a risk when using the intelligent wheelchair, such as when driving on a slope, if the wheelchair malfunctions at this time, the wheelchair will lose control and then the wheelchair will slide down the slope. Moreover, when such abnormal situations occur, the user is difficult to make a reasonable response in time, and the intelligent wheelchair also cannot provide an effective braking scheme, which is prone to safety accidents.

[0042] In related technologies, for the braking scheme of the electric device, a manually opened mechanical limiting device is usually provided to be manually braked by the user when abnormal situations such as sliding down the slope occur, but the occurrence of abnormal situations is accidental, and the user is difficult to take corresponding actions in time. In addition, for the braking scheme of the electric device, an electromagnetic brake device can also be installed inside the motor to be powered off when the motor control system is abnormal, thereby realizing braking, but the cost of this scheme is high, and it cannot cope with the scene of power supply abnormality of the electromagnetic brake device.

[0043] To this end, the embodiments of the present application provide a motor control system which detects the rotation direction when the motor rotates to determine the actual travel direction, and also detects the direction control signal to determine the travel direction in logical control, and judges whether the two directions are consistent, and then determines that the sliding down the slope phenomenon occurs in the case where the directions are inconsistent, and the motor is braked in time and effectively through the limit switch.

[0044] Figure 1 The principle block diagram of the motor control system provided by an embodiment of the present application is as follows, Figure 1As shown, in an embodiment, the motor control system comprises a main control module 110, a signal acquisition sensor 120, a limit driving module 130 and a limit switch 140.

[0045] The signal acquisition sensor 120 is configured to generate a corresponding sensor signal, which is a detection signal output by the signal acquisition sensor 120, i.e., the sensor signal is a signal for indicating the real-time rotation direction of the motor 210. In this regard, the detection input end of the signal acquisition sensor 120 is connected to the motor 210, and the output end of the signal acquisition sensor 120 is connected to the motor 210 detection end of the main control module 110. Optionally, the signal acquisition sensor 120 in some embodiments can be an encoder to detect the current actual travel direction of the motor 210 through the encoder. It is conceivable that the encoder can be divided into incremental and absolute types according to the hole pattern of the code disc, wherein the incremental encoder sends out a pulse signal every time a unit angle is turned, and the absolute value encoder sends out a unique binary value corresponding to the angle (such as distinguishing different values through signal amplitude, duty cycle, etc.) at every reference angle. In this regard, the sensor signal provided by the encoder can realize the detection of the rotation direction of the motor 210 during operation, i.e., to determine the above-mentioned current actual travel direction.

[0046] The input end of the main control module 110 is configured to access a direction control signal, which can be understood as a signal for driving the motor 210 to control the travel action and travel direction of the motor 210. Based on this, the main control module 110 can control the motor 210 to perform travel actions such as starting or stopping, and rotate in the clockwise direction or counterclockwise direction, wherein the rotation of the rotor in the motor 210 in the clockwise direction corresponds to one travel direction of the motor 210, so that the motorized device can move in one direction; the rotation of the rotor in the motor 210 in the counterclockwise direction corresponds to another travel direction of the motor 210, so that the motorized device can move in another direction. It should be noted that the direction control signal can be generated and provided by a higher-level circuit or control system module (or device) in response to the user's control action on the direction controller (such as a remote controller, a joystick, etc.).

[0047] In addition, the first output end of the main control module 110 is connected to the input end of the limit driving module 130, and the output end of the limit driving module 130 is connected to the limit switch 140, and the limit switch 140 is also configured to abut against the motor 210. The limit switch 140 is configured to limit the position or stroke of the mechanical movement, so that the movement machine automatically stops, reverses, changes speed, or automatically moves back and forth at a certain position or stroke. In this regard, the limit switch 140 can realize the braking of the motor 210.

[0048] The main control module 110 determines to generate the limit control signal according to the sensor signal and the direction control signal. Optionally, in an embodiment, the main control module 110 can be conceived to collect the rotating direction of the motor 210 in real time through the signal collection sensor 120 in the case that the rotating direction of the motor 210 corresponding to the sensor signal is different from the advancing direction corresponding to the direction control signal. The main control module 110 indicates the actual advancing direction by the direction, and based on this, the main control module 110 compares the indicated direction with the advancing direction corresponding to the direction control signal. In the case that the two are inconsistent, the main control module 110 can determine that the current slope slipping phenomenon occurs, and thus outputs the limit control signal to the limit driving module 130. The limit control signal is the signal output by the main control module 120 for triggering the limit driving module 130 to drive the limit switch, so that the limit driving module 130 drives the limit switch 140 in the case of receiving the limit control signal, so that the limit switch 140 brakes the motor 210, such as through the mechanical end thereon to abut against the motor 210 to make the motor 210 stop rotating.

[0049] Optionally, in an embodiment, the main control module is an MCU (Microcontroller Unit) module, so as to access the direction control signal and the sensor signal through the I / O interface provided by the MCU module, and then realize the judgment on whether there is a difference between the rotating direction of the motor and the advancing direction corresponding to the direction control signal through the integrated circuit thereon, so as to output the limit control signal to the limit driving module through another I / O interface thereon in the case that there is a difference. It should be noted that, in some embodiments, the main control module can also be a circuit module, such as a circuit module including a sampling circuit for realizing signal conversion based on an ADC (Analog to Digital Converter) and a comparison circuit for realizing comparison function based on a comparator, so as to realize sampling, quantization and comparison of the signal, thereby judging whether to output the limit control signal.

[0050] In one application scenario, when the motor control system of the application is applied to an electric device, such as an intelligent wheelchair, a user can control the movement of the intelligent wheelchair through a direction controller on the intelligent wheelchair. During the process of the user riding the intelligent wheelchair to climb a slope, the corresponding logical control direction (i.e., the direction of movement corresponding to the direction control signal) is the motor rotation direction along the slope upward. If the slope sliding phenomenon occurs, the actual direction of movement is the motor rotation direction along the slope downward, and the motor rotates in the opposite direction of the previous direction of movement. At this time, the intelligent wheelchair is difficult to achieve direction control. In this case, the main control module can determine that the intelligent wheelchair is difficult to achieve direction control according to the difference between the direction of movement corresponding to the direction control signal and the rotation direction of the motor.

[0051] For example, the motor rotation direction is detected by an incremental encoder. When the rotor of the motor rotates in the clockwise direction, it is positive and can make the intelligent wheelchair move upward along the slope. When the rotor of the motor rotates in the clockwise direction, the corresponding output pulse signal is a signal with positive pulse amplitude. When the slope sliding phenomenon occurs, the motor rotates in the opposite direction. In this case, the pulse signal output by the encoder is a signal with negative pulse amplitude. The main control module can determine that the rotation direction of the motor is different from the direction of movement corresponding to the direction control signal by comparison, and further determine that the slope sliding phenomenon occurs. The main control module sends a limit control signal to the limit driving module to drive the limit switch, thereby braking the motor and achieving brake control of the intelligent wheelchair to stop the rotation of the driving wheel of the intelligent wheelchair.

[0052] In addition, for example, the detection of the motor rotation direction can also use a Hall sensor as a signal acquisition sensor, where the Hall sensor can detect the change of the magnetic field. The motor itself has a Hall sensor for motor control. Alternatively, in one embodiment, for a motor without a built-in Hall element, a Hall sensor can also be installed on the side of the motor. In this case, when the motor rotates, the internal magnetic field will rotate with it, and the Hall sensor will output a pulse signal. Therefore, by detecting the sequence of the pulse signal, the rotation direction of the motor can be determined. For example, in a three-phase brushless motor, the positive and negative rotation of the motor can be accurately determined according to the different combination states and change sequences of the pulse signals output by the Hall sensor.

[0053] As can be seen from the above solution, the motor control system can determine whether the slope sliding phenomenon occurs by detecting the rotation direction of the motor, thereby braking the motor by driving the limit switch when the slope sliding phenomenon occurs, making the motor brake, and further completing effective braking to achieve the anti-slope sliding function. The control response of braking is timely, the system stability is good, and the safety of the electric device is improved.

[0054] In some embodiments, the current sensor can also be used as the signal collection sensor to detect the current change of the motor when the motor is running to determine whether the rotating direction of the motor is changed. For example, when the motor is running in the forward direction (e.g., rotating in the clockwise direction), the detected current change is consistent with the preset current change rule, and when the motor is running in the reverse direction (e.g., rotating in the counterclockwise direction), the detected current change is opposite to the preset current change rule.

[0055] Alternatively, in an embodiment, the sensor signal is a signal indicating that the direction is changed, such as the current change detected by the current sensor to determine whether the rotating direction of the motor is changed, and then a corresponding signal is provided. Therefore, after determining the sensor signal and the direction control signal, the master control module can also determine whether the coasting phenomenon occurs according to the change of the signal.

[0056] It is conceivable that, taking the direction in which the motor rotates clockwise as the direction in which the electric device moves forward as an example, in the uphill scenario (i.e., the scenario in which the user moves from the bottom of the slope to the top of the slope), the user controls the electric device to move uphill by the joystick, and at this time the direction control signal is used to indicate that the motor rotates clockwise. If the master control module receives a sensor signal indicating that the rotating direction of the motor is changed, and the master control module determines that the direction control signal has not changed, i.e., at this time the user still controls the electric device to move uphill but the motor reversely rotates, the master control module can determine that the current coasting phenomenon occurs, and then output the limit control signal. In the uphill scenario, if both the sensor signal and the direction control signal are changed, i.e., the user actively controls the electric device to move backward on the slope to return to the bottom of the slope, at this time the master control device determines that the coasting phenomenon does not occur, and does not output the limit control signal.

[0057] Similarly, in the downhill scenario (i.e., the scenario in which the user moves from the top of the slope to the bottom of the slope), the user controls the electric device to move downhill by the joystick, and at this time the direction control signal is used to indicate that the motor rotates clockwise. If the master control module determines that the direction control signal is changed, and the sensor signal corresponding to the rotating direction of the motor is not changed, at this time the user still controls the electric device to move backward to return to the top of the slope but the motor still rotates forward, the master control module can determine that the current coasting phenomenon occurs, and then output the limit control signal. In the downhill scenario, if both the sensor signal and the direction control signal are changed, i.e., the user actively controls the electric device to move backward on the slope to return to the top of the slope, at this time the master control device determines that the coasting phenomenon does not occur, and does not output the limit control signal.

[0058] In some embodiments, the limit driving module comprises a first switch unit, a second switch unit and a controllable limit unit. The control end of the first switch unit is connected to the first output end of the master control module, the signal output end of the first switch unit is connected to the control end of the second switch unit, the input end of the second switch unit is connected to a working voltage, the output end of the second switch unit is connected to the input end of the controllable limit unit, and the output end of the controllable limit unit is connected to the limit switch.

[0059] When the master control module outputs a limit control signal, the first switch unit receives the limit control signal through the control end thereof. In the case of receiving the limit control signal, the first switch unit outputs a conduction signal to the second switch unit, so that the second switch unit is turned on, thereby enabling the second switch unit to transmit the voltage signal (i.e. the working voltage) connected thereto to the controllable limit unit, and further enabling the controllable limit unit to provide a limit signal to the limit switch, thereby achieving the driving of the limit switch to complete the braking of the motor. It can be understood that in the limit driving module, the first switch unit and the second switch unit act as signal switches. The first switch unit is turned on when the limit control signal is connected, thereby providing a corresponding conduction signal for the second switch unit. The second switch unit is turned on when the conduction signal is connected.

[0060] Through the progressive control between the first switch unit and the second switch unit, the limit driving module provided by the embodiment can sequentially turn on the first switch unit and the second switch unit under the driving of the limit driving signal, thereby providing a conduction loop for the controllable limit unit to connect the working voltage, so as to achieve the driving of the limit switch to complete the braking of the motor. Moreover, the first switch unit and the second switch unit can stably respond to the limit driving signal, so as to avoid the misdriving of the limit switch caused by voltage fluctuation.

[0061] In an embodiment, the first switch unit comprises a first resistor, a second resistor, a third resistor, a fourth resistor and a first transistor. Specifically, the first end of the first resistor serves as the control end of the first switch unit, which is connected to the first output end of the master control module, and the second end of the first resistor is connected to the control end of the first transistor. The first end of the second resistor is connected to the control end of the first transistor, and the second end of the second resistor and the output end of the first transistor are both grounded. The first end of the third resistor is connected to the input end of the first transistor, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the working voltage.

[0062] Optionally, in an embodiment, the first transistor is an NPN transistor, wherein the base terminal of the NPN transistor is used as the control terminal of the first transistor, and the emitter terminal of the NPN transistor is used as the output terminal of the first transistor, and then a switch circuit is formed through the voltage division of the first resistor, the second resistor, the third resistor and the fourth resistor, and a corresponding voltage signal is output through the third resistor connected to the collector terminal of the NPN transistor. In this case, when the NPN transistor receives a limit control signal with a high level, the NPN transistor satisfies the conduction condition, and the NPN transistor is turned on.

[0063] It should be noted that in some embodiments, the first transistor can also be a PNP transistor, and a corresponding switch circuit can also be formed by using the PNP transistor to provide a corresponding voltage signal to the subsequent stage.

[0064] Therefore, the first switch unit can form a switch circuit by using the first transistor and the resistors connected to the terminals of the first transistor, so as to respond to the limit driving signal, which helps the limit driving module to respond to the limit driving signal more quickly, thereby improving the response speed of the motor control system to the brake control.

[0065] In addition, in some embodiments, the first transistor can also be an NMOS transistor, so as to form a corresponding switch circuit by using the NMOS transistor, and then when the limit driving signal is connected, the NMOS transistor is turned on, so as to turn on the first switch unit and provide a conduction signal for the second switch unit.

[0066] In an embodiment, the second switch unit includes a fifth resistor, a first capacitor, a second transistor, a second capacitor and a sixth resistor. Specifically, the first terminal of the fifth resistor is used as the control terminal of the second switch unit, and is connected to the signal output terminal of the first switch unit, and the second terminal of the fifth resistor is connected to the control terminal of the second transistor. The input terminal of the second transistor is connected to the working voltage, the first terminal of the first capacitor is connected to the input terminal of the second transistor, and the second terminal of the first capacitor is connected to the control terminal of the second transistor. The output terminal of the second transistor is used as the output terminal of the second switch unit, and is connected to the input terminal of the controllable limit unit, the first terminal of the second capacitor is connected to the output terminal of the second transistor, the second terminal of the second capacitor is grounded, and the sixth resistor is connected in parallel with the second capacitor. The parallel connection of the sixth resistor and the second capacitor can stabilize the output of the second transistor.

[0067] Optionally, in an embodiment, the second transistor is a PMOS transistor, the source terminal of the PMOS transistor is used as the input terminal and is connected to the working voltage, the gate terminal of the PMOS transistor is used as the control terminal and is connected to the fifth resistor to connect to a corresponding electrical signal through the fifth resistor, and the drain terminal of the PMOS transistor is used as the output terminal and is connected to the second capacitor. The second capacitor is also connected in parallel with the sixth resistor, and the parallel connection of the second capacitor and the sixth resistor can stabilize the voltage signal output by the drain terminal of the PMOS transistor.

[0068] It should be noted that in some embodiments, the second transistor can also be an NMOS transistor, the drain terminal of the NMOS transistor is connected to the working voltage, and the gate terminal of the NMOS transistor is connected to the fifth resistor to turn on the NMOS transistor and output a corresponding voltage signal through the source terminal of the NMOS transistor when receiving a corresponding electrical signal (i.e., the above-mentioned conduction signal).

[0069] Therefore, by controlling the on or off state of the second transistor, the limit driving module can stably drive the limit switch, so that the motor control system can stably brake the motor, which helps to improve the stability of the system.

[0070] In an embodiment, the controllable limit unit includes a normally closed switch, two ends of the normally closed switch are respectively used as an input end and an output end of the controllable limit unit, and the normally closed switch is used to provide the limit signal to the limit switch when the second switch unit receives the conduction signal, and to disconnect and stop providing the limit signal to the limit switch when the switch key of the normally closed switch is pressed.

[0071] It can be understood that the normally closed switch is a switch that is in a closed state without external force, and the normally closed switch remains in a closed state when the switch key thereon is not pressed. Therefore, when the second switch unit provides a limit signal after being turned on, the normally closed switch can transmit the signal to the limit switch to drive the limit switch because the normally closed switch is in a closed state. It can be imagined that when it is applied to an electric device, the motor control system of the present application can brake the motor in time when the electric device appears to be sliding down a slope. If the user needs to end the braking of the motor, he / she can press the switch key of the normally closed switch to make the normally closed switch disconnect, so that the limit switch no longer drives the motor, thereby ending the braking of the motor and restoring the normal operation of the motor.

[0072] Therefore, by setting the normally closed switch, the motor control system can quickly transmit the limit signal while providing the user with the function of quickly resetting, making the motor control system more reliable and helping to improve the user's experience.

[0073] Figure 2The circuit structure schematic diagram of the limiting driving module provided by an embodiment of the present application is shown in the figure. In an embodiment, the first switch unit includes a first transistor, which is an NPN transistor Q1, and the second transistor of the second switch unit is a PMOS transistor Q2. Specifically, the first switch unit further includes a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. The first end of the first resistor R1 is connected to the first output end of the master control module, and the second end of the first resistor R1 is connected to the base end of the NPN transistor Q1. The first end of the second resistor R2 is connected to the base end of the NPN transistor Q1, and the second end of the second resistor R2 and the emitter end of the NPN transistor Q1 are both grounded. The first end of the third resistor R3 is connected to the collector end of the NPN transistor Q1, the second end of the third resistor R3 is connected to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is connected to the working voltage VBUS.

[0074] The second switch unit further includes a fifth resistor R5, a first capacitor C1, a second capacitor C2, and a sixth resistor R6. Specifically, the first end of the fifth resistor R5 is connected to the second end of the third resistor R3, and the second end of the fifth resistor R5 is connected to the gate end of the PMOS transistor Q2. The source end of the PMOS transistor Q2 is connected to the working voltage VBUS, the first end of the first capacitor C1 is connected to the source end of the PMOS transistor Q2, and the second end of the first capacitor C1 is connected to the gate end of the PMOS transistor Q2. The first end of the second capacitor C2 is connected to the drain end of the PMOS transistor Q2, the second end of the second capacitor C2 is grounded, and the sixth resistor R6 is connected in parallel with the second capacitor C2.

[0075] The controllable limiting unit includes a normally closed switch K1, one end of the normally closed switch K1 is connected to the drain end of the PMOS transistor Q2, and the other end of the normally closed switch K1 is connected to the limiting switch.

[0076] It can be understood that when the base end of the NPN transistor Q1 is connected to a high-level signal, the NPN transistor Q1 is turned on, and correspondingly, the PMOS transistor Q2 also meets the turn-on condition. Due to the setting of the normally closed switch K1, the normally closed switch K1 can directly supply power to the limiting switch after the PMOS transistor Q2 is turned on, so as to drive the limiting switch to work and thereby brake the motor. Therefore, in actual application, the signal provided by the master control module to the NPN transistor Q1 can be set as a low-level signal in the normal use process, and a high-level limiting control signal output by the master control module can be used in the scene requiring braking.

[0077] To this end, the first switch unit forms a switch circuit through the NPN transistor thereon and the connected resistor, so as to further lower the voltage at the gate terminal of the PMOS transistor, so that the voltage at the gate terminal of the PMOS transistor quickly reaches the on voltage, so that the PMOS transistor is turned on more quickly, which helps the position limiting driving module to respond to the position limiting driving signal more quickly, thereby improving the response speed of the motor control system to the brake control.

[0078] In an embodiment, the position limiting driving module includes a motor driving unit and a mechanical position limiting unit, the input terminal of the motor driving unit is connected to the first output terminal of the master control module, the output terminal of the motor driving unit is connected to the input terminal of the mechanical position limiting unit, and the output terminal of the mechanical position limiting unit is used to drive the position limiting switch. It can be understood that the mechanical position limiting unit is a unit module for driving the position limiting switch, and the output terminal thereof can be a mechanical output terminal, so as to drive the position limiting switch to brake the motor in a mechanical braking manner. When the motor driving unit receives the position limiting control signal, the motor driving unit provides a pulse sequence signal, such as a PWM (Pulse Width Modulation) signal, an AB phase pulse signal, etc., to the mechanical position limiting unit in response to the position limiting control signal. The mechanical position limiting unit drives the position limiting switch in response to the received pulse sequence signal. The position limiting driving module drives the position limiting switch in a mechanical braking manner, which can provide a reliable braking manner for the motor control system, and helps to further improve the stability of the system.

[0079] Figure 3 The structure schematic diagram of the position limiting driving module provided for another embodiment of the present application is shown in the figure. In an embodiment, the motor driving unit includes four output terminals, and the pulse sequence signals output by the four output terminals of the motor driving unit are PWM signals. To this end, the motor driving unit can use a circuit module or device for generating a PWM signal in the related art, such as a timer chip U1, to provide a corresponding PWM signal after receiving the position limiting control signal.

[0080] The mechanical limiting unit includes a limiting motor M1, a first NMOS tube Q3, a second NMOS tube Q4, a third NMOS tube Q5, and a fourth NMOS tube Q6. Specifically, the gate end of the first NMOS tube Q3, the gate end of the second NMOS tube Q4, the gate end of the third NMOS tube Q5, and the gate end of the fourth NMOS tube Q6 are respectively connected to the PWM signals output by different output ends of the motor driving unit. The drain end of the first NMOS tube Q3 is connected to a working voltage, the source end of the first NMOS tube Q3 is connected to the drain end of the third NMOS tube Q5, and the source end of the third NMOS tube Q5 is grounded, that is, the first NMOS tube Q3 and the third NMOS tube Q5 are connected in series. The drain end of the second NMOS tube Q4 is connected to a working voltage, the source end of the second NMOS tube Q4 is connected to the drain end of the fourth NMOS tube Q6, and the source end of the fourth NMOS tube Q6 is grounded, that is, the second NMOS tube Q4 and the fourth NMOS tube Q6 are connected in series. The power supply end of the limiting motor M1 is connected to the source end of the first NMOS tube Q3 and the source end of the second NMOS tube Q4.

[0081] It can be understood that the first NMOS tube Q3, the second NMOS tube Q4, the third NMOS tube Q5, and the fourth NMOS tube Q6 can form a full-bridge driving circuit, and the limiting motor M1 is used to drive the limiting switch through the mechanical end in the working state. The limiting motor M1 has two working states of forward rotation and reverse rotation, and through different working states, the limiting motor M1 can drive the limiting switch through the mechanical end thereon, for example, the limiting motor M1 can drive the limiting switch to brake the motor when rotating forward.

[0082] The control of the working state of the limiting motor M1 can be realized through the PWM signals connected to the full-bridge driving circuit, for example, when the PWM signals connected to the first NMOS tube Q3 and the second NMOS tube Q4 are both high level and the PWM signals connected to the third NMOS tube Q5 and the fourth NMOS tube Q6 are both low level at the same time, the limiting motor M1 can rotate forward. For another example, when the PWM signals connected to the first NMOS tube Q3 and the second NMOS tube Q4 are both low level and the PWM signals connected to the third NMOS tube Q5 and the fourth NMOS tube Q6 are both high level at the same time, the limiting motor M1 can rotate reversely.

[0083] Therefore, the driving circuit of the limiting motor is formed by the NMOS tubes, so that the limiting motor can drive the limiting switch when in the working state, and the limiting driving module can realize the mechanical driving of the limiting switch through the limiting motor, which is helpful to further improve the stability of the system.

[0084] In an embodiment, in the case that the motor is a three-phase motor, the motor control system further comprises a pre-drive module and a three-phase inverter drive module, an input end of the pre-drive module is connected to the second output end of the master control module, an output end of the pre-drive module is connected to an input end of the three-phase inverter drive module, and three output ends of the three-phase inverter drive module are respectively connected to three corresponding different phase drive input ends of the three-phase motor.

[0085] Optionally, in an embodiment, the pre-drive module comprises an IGBT (Insulate-Gate Bipolar Transistor) driver, and the three-phase inverter drive module can adopt IGBT to form a drive circuit to realize phase switching. Specifically, six IGBTs are divided into three groups to control three phases of the three-phase motor respectively, two IGBTs in each group are connected in series, that is, the collector end of one IGBT is connected to a working voltage, and the emitter end of the IGBT is connected to the collector end of the other IGBT. Based on this, the IGBT driver controls the switching state of the IGBT and provides the necessary driving voltage and current to ensure the normal work of the IGBT, thereby realizing the scheme of using the IGBT driver to control the switching state of the IGBT to adjust the speed and torque of the motor.

[0086] The motor control system realizes driving control of the three-phase motor through the pre-drive module and the three-phase inverter drive module, and when applied to an electric device, it can ensure efficient energy conversion and accurate motor control, which helps to improve the performance of the electric device.

[0087] Figure 4 The structure schematic diagram of the motor control system provided by an embodiment of the present application is shown in the figure. In an embodiment, the motor control system comprises a master control module, a signal acquisition sensor, a limit driving module and a limit switch. The signal acquisition sensor is an encoder U3, which detects the rotation direction of the three-phase motor M2 and generates a sensor signal to be transmitted to the master control module. The master control module is an MCU module U2, which accesses the above-mentioned direction control signal and sensor signal through the I / O interface provided by the MCU module U2, and then judges whether there is a difference between the rotation direction of the three-phase motor M2 and the advancing direction corresponding to the direction control signal through the integrated circuit on it, so as to output a limit control signal to the limit driving module through another I / O interface on it in the case of difference.

[0088] The limiting driving module comprises a first switch unit, a second switch unit and a controllable limiting unit. The first switch unit comprises an NPN transistor Q1, a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4. The first end of the first resistor R1 is connected to the output end of the MCU module U2, and the second end of the first resistor R1 is connected to the base end of the NPN transistor Q1. The first end of the second resistor R2 is connected to the base end of the NPN transistor Q1, and the second end of the second resistor R2 and the emitter end of the NPN transistor Q1 are grounded. The first end of the third resistor R3 is connected to the collector end of the NPN transistor Q1, the second end of the third resistor R3 is connected to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is connected to the working voltage VBUS.

[0089] The second switch unit comprises a PMOS transistor Q2, a fifth resistor R5, a first capacitor C1, a second capacitor C2 and a sixth resistor R6. The first end of the fifth resistor R5 is connected to the second end of the third resistor R3, and the second end of the fifth resistor R5 is connected to the gate end of the PMOS transistor Q2. The source end of the PMOS transistor Q2 is connected to the working voltage VBUS, the first end of the first capacitor C1 is connected to the source end of the PMOS transistor Q2, and the second end of the first capacitor C1 is connected to the gate end of the PMOS transistor Q2. The first end of the second capacitor C2 is connected to the drain end of the PMOS transistor Q2, the second end of the second capacitor C2 is grounded, and the sixth resistor R6 is connected in parallel with the second capacitor C2. The controllable limiting unit comprises a normally closed switch K1, one end of the normally closed switch K1 is connected to the drain end of the PMOS transistor Q2, and the other end of the normally closed switch K1 is connected to the limiting switch U4.

[0090] Moreover, the motor used is a three-phase motor M2, and correspondingly, the electric control system further comprises a pre-driving module and a three-phase inverter driving module. The pre-driving module comprises an IGBT driver U5, and the three-phase inverter driving module can adopt an IGBT to form a driving circuit. Specifically, six IGBTs (such as Q7-Q12 in the figure) are divided into three groups to control three phases of the three-phase motor respectively. Each group has two IGBTs, and the two IGBTs in each group are connected in series, that is, the collector end of one IGBT is connected to the working voltage, and the emitter end of the IGBT is connected to the collector end of the other IGBT.

[0091] It can be understood that, in the normal operation of the system, the MCU module U2 controls the switching state of the IGBT through the IGBT driver U5 to adjust the rotating speed and torque of the motor, so as to realize the driving of the motor; and the MCU module U2 provides a low-level signal for the signal at the base end of the NPN transistor Q1, so that the NPN transistor Q1 does not meet the conduction condition, thereby making the system unable to brake the motor. In the scenario where braking is needed, the MCU module U2 provides a high-level signal for the base end of the NPN transistor Q1, when the base end of the NPN transistor Q1 is connected to the high-level signal, the NPN transistor Q1 is turned on, accordingly, the PMOS transistor Q2 also meets the conduction condition, due to the setting of the normally closed switch K1, after the PMOS transistor Q2 is turned on, the normally closed switch K1 can directly power the limit switch U4 to drive the limit switch U4 to work to brake the three-phase motor M2.

[0092] The embodiment of the present application also provides an electric device, which comprises the motor control system provided by the above embodiment, and the electric device can be an intelligent wheelchair or an electric cart in an embodiment. In this way, the electric device can automatically brake the motor and make the motor brake when the electric device is sliding down a slope, so as to realize the anti-slope sliding function, and the control response of the motor braking is timely, which is helpful to improve the safety of the electric device.

[0093] It should be noted that the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles, or devices including a series of elements not only include those elements, but also include other elements not explicitly listed, or other elements inherent to such processes, methods, articles, or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or device including the element.

[0094] It should be noted that the above is only a preferred embodiment of the present application and the technical principle applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, readjustments and substitutions without departing from the scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. An electric motor control system, characterized by, The device comprises a main control module, a signal acquisition sensor, a limit driving module and a limit switch. The detection input end of the signal acquisition sensor is connected with a motor, and the output end of the signal acquisition sensor is connected with the motor detection end of the main control module. The input end of the main control module is used for inputting a direction control signal, the first output end of the main control module is connected with the input end of the limit driving module. The output end of the limit driving module is connected with one end of the limit switch.

2. The motor control system of claim 1, wherein, The limit driving module comprises a first switch unit, a second switch unit and a controllable limit unit. The control end of the first switch unit is connected with the first output end of the main control module, and the signal output end of the first switch unit is connected with the control end of the second switch unit. The input end of the second switch unit is connected with a working voltage, the output end of the second switch unit is connected with the input end of the controllable limit unit, and the output end of the controllable limit unit is connected with the limit switch.

3. The motor control system of claim 2, wherein, The first switch unit comprises a first resistor, a second resistor, a third resistor, a fourth resistor and a first transistor. The first end of the first resistor is connected with the first output end of the main control module, the second end of the first resistor is connected with the control end of the first transistor, the first end of the second resistor is connected with the control end of the first transistor, and the second end of the second resistor and the output end of the first transistor are grounded. The first end of the third resistor is connected with the input end of the first transistor, the second end of the third resistor is connected with the first end of the fourth resistor, and the second end of the fourth resistor is connected with a working voltage.

4. The motor control system of claim 2 or 3, wherein, The second switch unit comprises a fifth resistor, a first capacitor, a second transistor, a second capacitor and a sixth resistor. The first end of the fifth resistor is connected with the signal output end of the first switch unit, the second end of the fifth resistor is connected with the control end of the second transistor, the input end of the second transistor is connected with a working voltage, the first end of the first capacitor is connected with the input end of the second transistor, and the second end of the first capacitor is connected with the control end of the second transistor. An output end of the second transistor is connected to an input end of the controllable limiting unit, a first end of the second capacitor is connected to an output end of the second transistor, a second end of the second capacitor is grounded, and the sixth resistor is connected in parallel with the second capacitor.

5. The motor control system of claim 4, wherein, The controllable limiting unit comprises a normally closed switch, two ends of the normally closed switch are respectively used as an input end and an output end of the controllable limiting unit, the normally closed switch is used to provide the limiting signal to the limiting switch when the second switch unit receives the enabling signal, and stop providing the limiting signal to the limiting switch when the normally closed switch is turned off.

6. The motor control system of claim 2 or 3 or 5, wherein, The first switch unit comprises a first transistor, and the first transistor is an NPN triode; and the second switch unit comprises a second transistor, and the second transistor is a PMOS transistor.

7. The motor control system of claim 1, wherein, The limiting driving module comprises a motor driving unit and a mechanical limiting unit, an input end of the motor driving unit is connected to a first output end of the main control module, an output end of the motor driving unit is connected to an input end of the mechanical limiting unit, and an output end of the mechanical limiting unit is used to drive the limiting switch. The motor driving unit is used to output a pulse sequence signal to the mechanical limiting unit when receiving the limiting control signal, and the mechanical limiting unit is used to drive the limiting switch when receiving the pulse sequence signal.

8. The motor control system of claim 7, wherein, The motor driving unit comprises four output ends, the pulse sequence signals output by the four output ends of the motor driving unit are PWM signals, and the mechanical limiting unit comprises a limiting motor, a first NMOS transistor, a second NMOS transistor, a third NMOS transistor and a fourth NMOS transistor. A gate end of the first NMOS transistor, a gate end of the second NMOS transistor, a gate end of the third NMOS transistor and a gate end of the fourth NMOS transistor are respectively connected to the pulse sequence signals output by different output ends of the motor driving unit. A drain end of the first NMOS transistor is connected to a working voltage, a source end of the first NMOS transistor is connected to a drain end of the third NMOS transistor, and a source end of the third NMOS transistor is grounded. A drain end of the second NMOS transistor is connected to a working voltage, a source end of the second NMOS transistor is connected to a drain end of the fourth NMOS transistor, and a source end of the fourth NMOS transistor is grounded. A power supply end of the limiting motor is connected to the source end of the first NMOS transistor and the source end of the second NMOS transistor, and the limiting motor is used to drive the limiting switch through a mechanical end in a working state.

9. The motor control system of claim 1, wherein, The motor is a three-phase motor, the motor control system further comprises a pre-driving module and a three-phase inverter driving module, an input end of the pre-driving module is connected to a second output end of the main control module, an output end of the pre-driving module is connected to an input end of the three-phase inverter driving module, and three output ends of the three-phase inverter driving module are respectively connected to three corresponding different phase driving input ends of the three-phase motor.

10. An electrically powered device, characterized by The electric device comprises the motor control system according to any one of claims 1-9.

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