Motor control system and mobile robot

Abstract

Embodiments of the present disclosure relate to the technical field of artificial intelligence, and provide a motor control system and a mobile robot, for improving the reliability of the motor control system braking a motor. The motor control system comprises a motor driver, a contactor, and a brake. The motor driver is electrically connected to a motor and is configured to control the operation state of the motor. The contactor is connected in series between a power supply and the motor driver and is configured to brake the motor. The brake is matched with the motor and is configured to brake the motor. The motor driver is further configured to control the contactor to brake the motor and control the brake to brake the motor. The motor control system is used for driving and braking a motor.

Description

Motor control system and mobile robot

[0001] This disclosure claims priority to the Chinese patent application filed with the China Patent Office on June 15, 2023, with application number 202321536805.9 and invention name “A Motor Control System and Mobile Robot,” the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0002] The present disclosure relates to the field of artificial intelligence technology, and in particular to a motor control system and a mobile robot. Background Art

[0003] A servo motor is an indirect speed-changing device. It boasts advantages such as a small electromechanical time constant, high linearity, and high position accuracy, making it widely used in mobile robots. Servo motors are driven and braked using a motor brake.

[0004] In related technologies, motor control systems use brakes or contactors to brake the motor. Both brakes and contactors can brake the motor. However, these brakes or contactors can malfunction, preventing the motor control system from quickly braking the motor, resulting in low braking reliability. During operation, if a mobile robot is about to collide with a worker or object, the motor control system may be unable to quickly brake the motor, preventing the mobile robot from stopping in time and potentially causing a collision, resulting in a safety accident. This poor safety and reliability of the mobile robot can also occur.

[0005] Summary of the Invention

[0006] An object of the embodiments of the present disclosure is to provide a motor control system and a mobile robot, which are used to improve the reliability of a braking motor of the motor control system.

[0007] To achieve the above objectives, the embodiments of the present disclosure provide the following technical solutions:

[0008] In one aspect, embodiments of the present disclosure provide a motor control system comprising a motor driver, a contactor, and a brake. The motor driver is electrically connected to the motor and configured to control the operating state of the motor. The contactor is connected in series between a power supply and the motor driver and configured to brake the motor. The brake, in conjunction with the motor, is configured to brake the motor. The motor driver is further configured to control the contactor to brake the motor and the brake to brake the motor.

[0009] In the disclosed embodiments, a motor driver controls the motor to lose power, causing the motor to inertially move. Simultaneously, the motor driver closes the normally open contacts of the contactor, generating a braking torque that prevents the motor from rotating, thereby reducing the motor's speed. Simultaneously, the motor driver controls the brake to clamp the motor, further reducing the motor's speed. This allows the motor's speed to drop rapidly, shortening the braking time. This allows the mobile robot to stop promptly when it is about to collide with a worker or object, reducing the risk of a safety accident and improving the safety and reliability of the mobile robot.

[0010] In some embodiments, the holding brake includes a holding brake coil, and the contactor includes a contactor coil. The motor driver includes a controller, a first voltage signal terminal, a holding brake coil control circuit, and a contactor coil control circuit. The controller is electrically connected to the motor and configured to control the motor's operating state. The holding brake coil control circuit includes a first transistor, a first electrode electrically connected to the first voltage signal terminal, a second electrode electrically connected to the first end of the holding brake coil, and a gate electrically connected to the controller. The second end of the holding brake coil is grounded. The contactor coil control circuit includes a second transistor, a first electrode electrically connected to the first voltage signal terminal, a second electrode electrically connected to the first end of the contactor coil, and a gate electrically connected to the controller. The second end of the contactor coil is grounded. The controller is further configured to control the first transistor to be on or off to control the holding brake to brake the motor, and to control the second transistor to be on or off to control the contactor to brake the motor.

[0011] In some embodiments, the first transistor is an N-type transistor or a P-type transistor, and the controller includes a first control unit and a second control unit. The brake coil control circuit also includes a first AND circuit, wherein an output terminal of the first AND circuit is electrically connected to the gate of the first transistor, a first input terminal is electrically connected to the first control unit, and a second input terminal is electrically connected to the second control unit. The signal transmitted by the first control unit to the first AND circuit is the same as the signal transmitted by the second control unit to the first AND circuit.

[0012] In some embodiments, the brake coil control circuit further includes a third transistor, wherein a first electrode of the third transistor is electrically connected to the second end of the brake coil, a second electrode is grounded, and a gate is electrically connected to the controller. The controller is further configured to transmit a first pulse width modulation signal to the third transistor and to change a duty cycle of the first pulse width modulation signal.

[0013] In some embodiments, the third transistor is an N-type transistor or a P-type transistor, and the controller includes a third control unit and a fourth control unit. The brake coil control circuit also includes a second AND circuit, wherein the output terminal of the second AND circuit is electrically connected to the gate of the third transistor, the first input terminal is electrically connected to the third control unit, and the second input terminal is electrically connected to the fourth control unit. The third control unit is configured to transmit the first pulse-width modulated signal to the second AND circuit and change the duty cycle of the first pulse-width modulated signal, and the fourth control unit is configured to control the conduction or cutoff of the third transistor.

[0014] In some embodiments, the brake coil control circuit further includes a first sampling resistor and a first comparator. One end of the first sampling resistor is electrically connected to the second electrode of the third transistor, and the other end is grounded. The first sampling resistor is configured to collect a first voltage value of the branch circuit in which the brake coil is located. The first comparator has an output end electrically connected to the controller and an input end electrically connected to the first sampling resistor. The comparator is configured to receive the first voltage value collected by the first sampling resistor and determine the magnitude of the first voltage value relative to a first reference voltage value. If the first voltage value is greater than the first reference voltage value, the first comparator transmits a first cutoff signal to the controller. The controller, upon receiving the first cutoff signal, sets the duty cycle of the first pulse-width modulated signal to zero. If the first voltage value is less than or equal to the first reference voltage value, the first comparator transmits a first stabilization signal to the controller. The controller, upon receiving the first stabilization signal, maintains the duty cycle of the first pulse-width modulated signal constant.

[0015] In some embodiments, the second transistor is an N-type transistor or a P-type transistor, and the controller includes a fifth control unit and a sixth control unit. The contactor coil control circuit also includes a third AND circuit, wherein an output terminal of the third AND circuit is electrically connected to the gate of the second transistor, a first input terminal is electrically connected to the fifth control unit, and a second input terminal is electrically connected to the sixth control unit. The signal transmitted by the fifth control unit to the third AND circuit is the same as the signal transmitted by the sixth control unit to the third AND circuit.

[0016] In some embodiments, the contactor coil control circuit further includes a fourth transistor, wherein a first electrode of the fourth transistor is electrically connected to the second end of the contactor coil, a second electrode of the fourth transistor is grounded, and a gate of the fourth transistor is electrically connected to the controller. The controller is configured to transmit a second pulse width modulation signal to the fourth transistor and change a duty cycle of the second pulse width modulation signal.

[0017] In some embodiments, the fourth transistor is an N-type transistor or a P-type transistor, and the controller includes a seventh control unit and an eighth control unit. The contactor coil control circuit also includes a fourth AND circuit, wherein the output of the fourth AND circuit is electrically connected to the gate of the fourth transistor, the first input of the fourth AND circuit is electrically connected to the seventh control unit, and the second input of the eighth control unit is electrically connected. The seventh control unit is configured to transmit a second pulse width modulation signal to the fourth AND circuit and change the duty cycle of the second pulse width modulation signal, and the eighth control unit is configured to turn on or off the fourth transistor.

[0018] In some embodiments, the contactor coil control circuit further includes a second sampling resistor and a second comparator. One end of the second sampling resistor is electrically connected to the second electrode of the fourth transistor, and the other end is grounded. The second comparator is configured to collect a second voltage value of the branch in which the contactor coil is located. The output end of the second comparator is electrically connected to the controller, and the input end is electrically connected to the second sampling resistor. The second comparator is configured to receive the second voltage value collected by the second sampling resistor and determine the magnitude of the second voltage value relative to a second reference voltage value. If the second voltage value is greater than the second reference voltage value, the second comparator transmits a second cutoff signal to the controller. The controller receives the second cutoff signal and sets the duty cycle of the second pulse width modulation signal to zero. If the second voltage value is less than or equal to the second reference voltage value, the second comparator transmits a second stabilization signal to the controller. The controller receives the second stabilization signal and maintains the duty cycle of the second pulse width modulation signal unchanged.

[0019] In some embodiments, the controller further includes a first processor and a second processor, the first control unit, the third control unit, the fifth control unit and the seventh control unit are located in the first processor, and the second control unit, the fourth control unit, the sixth control unit and the eighth control unit are located in the second processor.

[0020] On the other hand, a mobile robot is provided, comprising the motor control system of any one of the above embodiments.

[0021] The above-mentioned mobile robot has the same structure and beneficial technical effects as the motor control system provided in some of the above-mentioned embodiments, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions of the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of the present disclosure.

[0023] FIG1 is a block diagram of a motor control system according to some embodiments;

[0024] FIG2 is a control circuit diagram according to some embodiments;

[0025] FIG3 is a block diagram of a controller including a first processor and a second processor according to some embodiments. DETAILED DESCRIPTION

[0026] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0027] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as having an open, inclusive meaning, that is, "including, but not limited to." In the description of the specification, the terms "one embodiment," "some embodiments," "exemplary embodiments," "examples," or "some examples" are intended to indicate that specific features, structures, materials, or characteristics associated with the embodiment or example are included in the embodiments or examples of the present disclosure. The schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials, or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0028] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0029] When describing some embodiments, the word "connected" and its derivatives may be used. The term "connected" should be understood in a broad sense. For example, "connected" can mean fixed connection, detachable connection, or integration; it can be directly connected or indirectly connected through an intermediate medium.

[0030] As used herein, the term "if" is optionally interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined that" or "if [stated condition or event] is detected" are optionally interpreted to mean "upon determining" or "in response to determining" or "upon detecting [stated condition or event]" or "in response to detecting [stated condition or event]," depending on the context.

[0031] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0032] The control electrode of each transistor used in this document is the gate of the transistor, the first electrode is one of the source and drain of the transistor, and the second electrode is the other of the source and drain of the transistor. Since the source and drain of the transistor can be symmetrical in structure, the source and drain can be structurally indistinguishable. In other words, the first electrode and the second electrode of the transistor in the embodiments of the present disclosure can be structurally indistinguishable. For example, in the case where the transistor is a P-type transistor, the first electrode of the transistor is the source and the second electrode is the drain; for example, in the case where the transistor is an N-type transistor, the first electrode of the transistor is the drain and the second electrode is the source.

[0033] The embodiments of the present disclosure provide a mobile robot, which is a machine device that performs work automatically. It can accept human commands, run pre-programmed programs, and act according to principles and guidelines formulated using artificial intelligence technology.

[0034] Mobile robots can be divided into wheeled mobile robots, walking mobile robots, snake-like robots, tracked mobile robots and crawling robots according to their movement mode; they can be divided into medical robots, handling robots, assistance robots and cleaning robots according to their functions and uses.

[0035] In some embodiments, the mobile robot includes a motor control system 100 . As shown in FIG. 1 , the motor control system 100 includes a power supply 10 , a motor driver 30 , a contactor 40 , and a brake 50 .

[0036] The motor driver 30 is connected to the motor 20 and is used to control the operating state of the motor 20. For example, the motor driver 30 controls the speed of the motor 20.

[0037] The motor driver 30 includes a motor drive circuit, a brake control circuit, a voltage acquisition unit, a current acquisition unit, a temperature acquisition unit, and a control unit, among other components, which are not specifically listed in the embodiments of this disclosure. The motor driver 30 also includes a logic power supply and a power supply. The power supply supplies power to the motor 20 via the motor drive circuit, while the logic power supply supplies power to the brake control circuit and various other components.

[0038] The contactor 40 is connected in series between the power supply 10 and the motor driver 30. The power supply 10 supplies power to the motor 20 via the motor drive circuit in the motor driver 30, so that the motor 20 rotates.

[0039] In some implementations, when the contactor 40 is disconnected, the power supply 10 cannot supply power to the motor 20, and the motor 20 decelerates until it stops moving. That is, the motor driver 30 controls the contactor 40 to brake the motor 20. Braking refers to reducing the speed of the motor 20 or stopping the motor 20.

[0040] In other embodiments, the motor driver 30 controls the normally closed contacts of the contactor 40 to disconnect, and the motor 20 loses power and moves by inertia. At the same time, the motor driver 30 controls the normally open contacts of the contactor 40 to close, so that the motor 20 generates a braking torque to prevent the motor 20 from rotating. Under the action of the braking torque, the speed of the motor 20 drops rapidly, that is, the motor driver 30 controls the contactor 40 to brake the motor 20.

[0041] The braking of the contactor 40 includes reverse braking or dynamic braking, which are not listed one by one in the embodiments of the present disclosure.

[0042] In the case where the contactor 40 braking includes reverse braking, the braking process of the contactor 40 is as follows: the normally closed contact of the contactor 40 (the contact that is in a closed state when power is not supplied) is disconnected, the motor 20 loses power and moves by inertia, and at the same time, the normally open contact of the contactor 40 (the contact that is in an open state when power is not supplied) is closed to change the phase sequence of the power supply 10, and the motor 20 generates a braking torque that prevents the motor 20 from rotating. Under the action of the braking torque, the speed of the motor 20 drops rapidly. When the speed of the motor 20 is less than the speed threshold (for example, the speed threshold is 50r / min or 100r / min), the normally open contact of the contactor 40 is disconnected, and the reverse braking ends. It is understandable that the normally closed contact of the contactor 40 can also be a normally open contact, and the braking process of the contactor 40 can be adaptively designed.

[0043] When contactor 40 braking involves dynamic braking, the braking process is as follows: The normally closed contacts of contactor 40 open, causing motor 20 to inertially move upon power loss. Simultaneously, the normally open contacts of contactor 40 close, connecting a DC power source to motor 20 and generating a static DC magnetic field. The inertial motion of motor 20 cuts through the DC magnetic field, generating an induced current. The interaction between the DC magnetic field and the induced current generates a braking torque that prevents motor 20 from rotating. The speed of motor 20 rapidly decreases. When the speed of motor 20 reaches 0 r / min, there is no relative motion between motor 20 and the DC magnetic field, and the induced current, i.e., the braking torque, disappears. Motor 20 stops rotating, and dynamic braking ends.

[0044] Brake 50 and motor 20 cooperate to brake motor 20. The process by which motor driver 30 controls brake 50 to brake motor 20 is as follows: motor driver 30 controls motor 20 to lose power, causing motor 20 to coast. Motor driver 30 also controls brake 50 to clamp motor 20, rapidly decreasing the speed of motor 20 to 0 r / min, and braking by brake 50 ends.

[0045] The motor control system 100 provided by the embodiments of the present disclosure includes a brake 50 and a contactor 40. The combined braking process of the brake 50 and contactor 40 is as follows: the motor driver 30 controls the motor 20 to de-energize, causing the motor 20 to coast. Simultaneously, the motor driver 30 closes the normally open contacts of the contactor 40, generating a braking torque that prevents the motor 20 from rotating, thereby reducing its speed. Simultaneously, the motor driver 30 controls the brake 50 to clamp the motor 20, further reducing its speed. This allows the motor 20's speed to drop rapidly, shortening its braking time. This allows the mobile robot to stop promptly when it is about to collide with a worker or object, reducing the risk of a safety accident and improving the safety and reliability of the mobile robot. This allows the mobile robot to meet the requirements of Performance Level (PL) d-Category 3 and pass functional safety certification.

[0046] In some embodiments, as shown in FIG. 2 , the contactor 40 includes a contactor coil 41 , and the brake 50 includes a brake coil 51 .

[0047] The motor driver 30 includes a controller 31 , a first voltage signal terminal 32 , a brake coil control circuit 33 , and a contactor coil control circuit 34 .

[0048] The controller 31 is electrically connected to the motor 20 and is used to control the operation of the motor 20. For example, the controller 31 controls the speed of the motor 20.

[0049] The controller 31 refers to a device that can generate an operation control signal based on the instruction operation code and the timing signal to instruct the motor control system 100 to execute the control instruction. Exemplarily, the controller 31 may include a central processing unit (CPU), a general-purpose processor network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a microprocessor, a programmable logic device (PLD), or any combination thereof. The controller 31 may also be other devices with processing functions, such as circuits, devices, or software modules, and the embodiments of the present disclosure do not impose any restrictions on this. For example, the controller 31 includes an MCU.

[0050] The voltage value of the first voltage signal terminal 32 may include 12V, 24V, or 36V, which are not listed one by one in the embodiments of the present disclosure. For example, the voltage value of the first voltage signal terminal 32 is 24V.

[0051] The brake coil control circuit 33 includes a first transistor 331. The first transistor 331 can be a thin film transistor (TFT), a field effect transistor (FET), or other switching devices with similar characteristics. In the embodiments of the present disclosure, field effect transistors are used as an example for description.

[0052] The field effect transistor may include a junction field effect transistor (JFET) or a metal oxide field effect transistor (MOS-FET), which is not specifically limited in the present embodiment. For example, the first transistor 331 includes a metal oxide field effect transistor.

[0053] In addition, in the circuits provided in the embodiments of the present disclosure, transistors are all described using N-type transistors as an example. It should be noted that the embodiments of the present disclosure include but are not limited to this. For example, one or more transistors in the circuits provided in the embodiments of the present disclosure may also be P-type transistors (adjusted here according to the specific scheme), and it is only necessary to connect the respective poles of the selected type of transistors with reference to the respective poles of the corresponding transistors in the embodiments of the present disclosure, and to make the corresponding voltage terminals provide the corresponding high voltage or low voltage.

[0054] The first transistor 331 has a first electrode electrically connected to the first voltage signal terminal 32, a second electrode electrically connected to the first end of the brake coil 51, and a gate electrically connected to the controller 31. The controller 31 is configured to control the conduction or cutoff of the first transistor 331. For example, if the first transistor 331 is an N-type transistor, the controller 31 transmits a low voltage signal to the gate of the first transistor 331 to turn it off. In this case, the first and second electrodes of the first transistor 331 are disconnected, and the first voltage signal terminal 32 is also disconnected from the brake coil 51. Alternatively, the controller 31 transmits a high voltage signal to the gate of the first transistor 331 to turn it on. In this case, the first and second electrodes of the first transistor 331 are connected, and the first voltage signal terminal 32 is also connected to the brake coil 51. The second end of the brake coil 51 is grounded.

[0055] Therefore, if the mobile robot is about to collide with a person or object, the controller 31 transmits a non-operating voltage signal (a non-operating voltage is a voltage that does not turn on the operated transistor included in the non-operating voltage) to the gate of the first transistor 331. This turns off the first transistor 331, de-energizing the brake coil 51, and eliminating the electromagnetic force. If the first transistor 331 is an N-type transistor, the non-operating voltage signal can be a low voltage signal.

[0056] For example, the mobile robot may be equipped with a distance sensor to detect whether an object is within a certain distance in front of the mobile robot and, when an object is detected in front of the mobile robot, to measure the distance between the object and the mobile robot. The controller 31 may obtain the distance detected by the distance sensor. If the obtained distance is small, such as less than a preset distance threshold, indicating that the mobile robot is about to collide with the object, the controller 31 transmits a non-operating voltage signal to the gate of the first transistor 331, turning off the first transistor 331 and de-energizing the brake coil 51, thereby eliminating the electromagnetic force of the brake coil 51.

[0057] The brake 50 also includes an armature, a spring, and a brake shoe. When the brake coil 51 loses power and electromagnetic force, the armature loses its magnetism, freeing the spring from resistance. Under the action of the spring's elastic force, the brake shoe clamps the motor 20, rapidly reducing the speed of the motor 20 and allowing the mobile robot to stop moving promptly. This reduces the risk of accidents and improves the safety and reliability of the mobile robot.

[0058] The contactor coil control circuit 34 includes a second transistor 341. A first terminal of the second transistor 341 is electrically connected to the first voltage signal terminal 32, a second terminal is electrically connected to the first terminal of the contactor coil 41, and a gate is electrically connected to the controller 31. The controller 31 is configured to control the conduction or cutoff of the second transistor 341. For example, if the second transistor 341 is an N-type transistor, the controller 31 transmits a low voltage signal to the gate of the second transistor 341 to cut off the second transistor 341, or transmits a high voltage signal to turn the second transistor 341 on. The second terminal of the contactor coil 41 is grounded.

[0059] The type of the second transistor 341 may be the same as that of the first transistor 331 . For example, both the first transistor 331 and the second transistor 341 may be N-type transistors.

[0060] The type of the second transistor 341 may also be different from the type of the first transistor 331 . For example, the first transistor 331 is an N-type transistor, and the type of the second transistor 341 is a P-type transistor.

[0061] Therefore, if the mobile robot is about to hit a staff member or an object, the controller 31 transmits a non-working voltage signal to the gate of the second transistor 341, the second transistor 341 is cut off, the contactor coil 41 loses power, the contactor coil 41 has no electromagnetic force, the normally closed contact of the contactor 40 is disconnected, the motor 20 loses power and moves by inertia, and at the same time the normally open contact of the contactor 40 is closed, and the motor 20 generates a braking torque to prevent the motor 20 from rotating. Under the action of the braking torque, the speed of the motor 20 drops rapidly, so that the mobile robot can stop moving in time, reducing the risk of safety accidents of the mobile robot and improving the safety and reliability of the mobile robot.

[0062] In some embodiments, as shown in Figure 2, the first transistor 331 is an N-type transistor. The controller 31 further includes a first control unit 311 and a second control unit 312. The first control unit 311 and the second control unit 312 may each include an MCU.

[0063] The brake coil control circuit 33 also includes a first AND circuit 332. At this time, the first control unit 311 and the second control unit 312 are electrically connected to the two input ends of the first AND circuit 332 respectively, and the output end of the first AND circuit 332 is electrically connected to the gate of the first transistor 331, thereby realizing the electrical connection between the controller 31 and the first transistor 331.

[0064] The output terminal of the first AND circuit 332 is electrically connected to the gate of the first transistor 331. In this way, the controller 31 uses the voltage signal transmitted to the first AND circuit 332 by the first control unit 311 and the second control unit 312 to control the voltage signal transmitted from the output terminal of the first AND circuit 332 to the gate of the first transistor 331, thereby controlling the conduction or cutoff of the first transistor 331.

[0065] For example, when the first transistor 331 is an N-type transistor, the first AND circuit 332 transmits a low voltage signal to the gate of the first transistor 331 to turn off the first transistor 331 , or transmits a high voltage signal to turn on the first transistor 331 .

[0066] The first input terminal of the first AND circuit 332 is electrically connected to the first control unit 311, and the second input terminal is electrically connected to the second control unit 312. The signal transmitted by the first control unit 311 to the first AND circuit 332 is the same as the signal transmitted by the second control unit 312 to the first AND circuit 332.

[0067] When the first control unit 311 transmits a high-voltage signal to the first AND circuit 332, and the second control unit 312 also transmits a high-voltage signal to the first AND circuit 332, the output of the first AND circuit 332 transmits the high-voltage signal to the gate of the first transistor 331. Because the first transistor 331 is an N-type transistor, the high-voltage signal turns on the first transistor 331, energizing the brake coil 51.

[0068] When the first control unit 311 transmits a low-voltage signal to the first AND circuit 332, and / or the second control unit 312 transmits a low-voltage signal to the first AND circuit 332, the output terminal of the first AND circuit 332 transmits the low-voltage signal to the gate of the first transistor 331. Because the first transistor 331 is an N-type transistor, the low-voltage signal turns off the first transistor 331, de-energizing the brake coil 51, and the brake 50 brakes the motor 20. This improves operational efficiency and provides more stable and reliable braking of the motor 20.

[0069] During signal transmission, noise, pulse jitter, a poor external battery environment, or other factors can corrupt the signal during transmission, resulting in bit errors. For example, if the signal transmitted by controller 31 is a low-voltage signal (a low-voltage signal can turn off first transistor 331), the signal may be corrupted during transmission, and the signal received by first transistor 331 may be a high-voltage signal. First transistor 331 turns on, energizing brake coil 51. Brake 50 cannot brake motor 20, resulting in the mobile robot being unable to stop in time and having low safety and reliability.

[0070] Thus, if the mobile robot is about to collide with a person or object, the first control unit 311 and the second control unit 312 each transmit a low-voltage signal to the first AND circuit 332. During the signal transmission process, at least one of the low-voltage signal transmitted by the first control unit 311 to the first AND circuit 332 and the low-voltage signal transmitted by the second control unit 312 to the first AND circuit 332 remains unchanged. The output end of the first AND circuit 332 transmits a low-voltage signal to the first transistor 331, turning off the first transistor 331. The brake coil 51 loses its electromagnetic force, and under the action of the spring force, the brake shoe clamps the motor 20, rapidly reducing the speed of the motor 20. The brake 50 brakes the motor 20, allowing the mobile robot to stop moving in a timely manner, reducing the risk of safety accidents involving the mobile robot and improving the safety and reliability of the mobile robot. The present disclosure utilizes the first transistor 331 and the first AND circuit 332 to promptly brake the motor 20 and stop the mobile robot, thereby improving safety and reliability.

[0071] In some embodiments, as shown in FIG. 2 , the brake coil control circuit 33 further includes a third transistor 333 .

[0072] The type of the third transistor 333 can be the same as the type of the aforementioned transistors, that is, the type of the third transistor 333 can be the same as the type of the first transistor 331 and the second transistor 341. For example, the first transistor 331, the second transistor 341 and the third transistor 333 are all N-type transistors.

[0073] The type of the third transistor 333 may also be different from the types of the aforementioned transistors. For example, the first transistor 331 and the second transistor 341 are both N-type transistors, and the third transistor 333 is a P-type transistor.

[0074] The first electrode of the third transistor 333 is electrically connected to the second end of the brake coil 51 , and the second electrode is grounded, thereby grounding the second end of the brake coil 51 . The gate of the third transistor 333 is electrically connected to the controller 31 .

[0075] The controller 31 is further configured to control the on / off state of the third transistor 333. For example, when the third transistor 333 is an N-type transistor, the controller 31 transmits a low voltage signal to the gate of the third transistor 333 to turn off the third transistor 333, or transmits a high voltage signal to the gate of the third transistor 333 to turn on the third transistor 333.

[0076] When controlling the operation of the motor 20, the controller 31 transmits a first pulse width modulation (PWM) signal to the third transistor 333. The controller 31 changes the duty cycle of the first PWM signal (duty cycle refers to the proportion of the energized time relative to the total energized time within a pulse cycle) to alter the ratio of the energized time of the brake coil 51 to the total energized time. This, in turn, changes the effective voltage across the brake coil 51 (the average voltage across the coil within a pulse cycle). This ensures that the effective voltage across the brake coil 51 matches the rated voltage of the brake coil 51, thereby extending the service life of the brake coil 51.

[0077] For example, if the duty cycle of the first pulse width modulation signal is 0.6, then within a pulse period T, the on-time is 0.6T and the off-time is 0.4T. During the on-time of 0.6T, it can be considered that the controller 31 transmits a high voltage signal to the gate of the third transistor 333, turning on the third transistor 333. At this time, the second end of the brake coil 51 is grounded, current flows through the brake coil 51, and a voltage, denoted as U1, exists across the brake coil 51. During the off-time of 0.4T, it can be considered that the controller 31 does not transmit a voltage signal to the gate of the third transistor 333, or transmits a low voltage signal, turning off the third transistor 333. At this time, the second end of the brake coil 51 is in an open-circuit state, no current flows through the brake coil 51, and no voltage exists across the brake coil 51. Thus, within a pulse period T, the brake coil 51 has a voltage, U1, for 0.6T, with an average voltage of 0.6U1.

[0078] 2 , the third transistor 333 is an N-type transistor. The controller 31 further includes a third control unit 313 and a fourth control unit 314 .

[0079] The brake coil control circuit 33 also includes a second AND circuit 334. At this time, the third control unit 313 and the fourth control unit 314 are electrically connected to the two input ends of the second AND circuit 334 respectively, and the output end of the second AND circuit 334 is electrically connected to the gate of the third transistor 333, thereby realizing the electrical connection between the controller 31 and the third transistor 333.

[0080] The output end of the second AND circuit 334 is electrically connected to the gate of the third transistor 333. In this way, the controller 31 uses the voltage signal transmitted to the second AND circuit 334 by the third control unit 313 and the fourth control unit 314 to control the voltage signal output from the output end of the second AND circuit 334, thereby controlling the conduction or cutoff of the third transistor 333.

[0081] For example, when the third transistor 333 is an N-type transistor, the third control unit 313 and the fourth control unit 314 both transmit a low voltage signal to the second AND circuit 334, so that the output end of the second AND circuit 334 outputs a low voltage signal, and the output end of the second AND circuit 334 transmits a low voltage signal to the gate of the third transistor 333, so that the third transistor 333 is cut off, or the third control unit 313 and the fourth control unit 314 both transmit a high voltage signal to the second AND circuit 334, so that the output end of the second AND circuit 334 outputs a high voltage signal, and the second AND circuit 334 transmits a high voltage signal to the gate of the third transistor 333, so that the third transistor 333 is turned on.

[0082] A first input terminal of the second AND circuit 334 is electrically connected to the third control unit 313 , and a second input terminal of the second AND circuit 334 is electrically connected to the fourth control unit 314 .

[0083] When the mobile robot is operating normally, the third control unit 313 transmits a first pulse-width modulated signal to the second AND circuit 334. The third control unit 313 can change the effective voltage across the brake coil 51 by varying the duty cycle of the first pulse-width modulated signal, thereby matching the effective voltage across the brake coil 51 with the rated voltage of the brake coil 51. Because the pulse period of a pulse-width modulated signal is typically short, the power-off time within a pulse period is even shorter. Therefore, the first pulse-width modulated signal transmitted by the third control unit 313 to the second AND circuit 334 can be considered a high-voltage signal.

[0084] The fourth control unit 314 is configured to control the signal outputted from the output terminal of the second AND circuit 334. When the third control unit 313 transmits a high-voltage signal to the second AND circuit 334, if the signal transmitted by the fourth control unit 314 to the second AND circuit 334 is a low-voltage signal within a pulse cycle, the signal outputted from the output terminal of the second AND circuit 334 is a low-voltage signal, the second AND circuit 334 transmits the low-voltage signal to the gate of the third transistor 333, and the third transistor 333 is turned off. If the signal transmitted by the fourth control unit 314 to the second AND circuit 334 is a high-voltage signal, the signal outputted from the output terminal of the second AND circuit 334 is a high-voltage signal, the second AND circuit 334 transmits a high-voltage signal to the gate of the third transistor 333, and the third transistor 333 is turned on.

[0085] If the mobile robot is about to collide with a person or object, the third control unit 313 and the fourth control unit 314 each transmit a low-voltage signal to the second AND circuit 334. During the signal transmission process, at least one of the low-voltage signal transmitted by the third control unit 313 to the second AND circuit 334 and the low-voltage signal transmitted by the fourth control unit 314 to the second AND circuit 334 remains unchanged. The output end of the second AND circuit 334 transmits a low-voltage signal to the third transistor 333, turning off the third transistor 333. The brake coil 51 loses its electromagnetic force, and under the action of the spring force, the brake shoe clamps the motor 20, rapidly reducing the speed of the motor 20. The brake 50 brakes the motor 20, stopping the mobile robot in a timely manner, reducing the risk of safety accidents and improving the safety and reliability of the mobile robot.

[0086] In some embodiments, as shown in FIG. 2 , the brake coil control circuit 33 further includes a first sampling resistor 335 and a first comparator 336 .

[0087] One end of the first sampling resistor 335 is electrically connected to the second electrode of the third transistor 333 , and the other end of the first sampling resistor 335 is grounded, so that the second electrode of the third transistor 333 is grounded.

[0088] The first sampling resistor 335 is used to collect a first voltage value of the branch where the brake coil 51 is located.

[0089] The output terminal of the first comparator 336 is electrically connected to the controller 31, and the input terminal is connected to the first sampling resistor 335. The first comparator 336 is used to receive the first voltage value collected by the first sampling resistor 335 and determine the difference between the first voltage value and the first reference voltage value.

[0090] The value of the first reference voltage value can be selected based on the rated voltage value of the brake coil 51, or can be set by the staff according to actual conditions. The embodiments of the present disclosure do not specifically limit this. For example, the first reference voltage value can be less than the rated voltage value of the brake coil 51. For example, the value of the first reference voltage value is 3V. The resistance value of the first sampling resistor 335 is fixed. Then, the greater the current flowing through the first sampling resistor 335, the greater the voltage of the first sampling resistor 335. Therefore, the first comparator 336 formally compares voltage values, but in principle compares current values.

[0091] If the first comparator 336 compares the first voltage value to be greater than the first reference voltage value, it indicates that the voltage across the first sampling resistor 335 is greater, and the current flowing through the first sampling resistor 335 is greater. In other words, the current in the branch path where the first sampling resistor 335 is located is greater. Since the brake coil 51 is a component in the branch path where the first sampling resistor 335 is located, the current flowing through the brake coil 51 is also greater, potentially damaging the brake coil 51. In this case, the first comparator 336 can transmit a first cutoff signal to the controller 31. The controller 31 receives the first cutoff signal, setting the duty cycle of the first pulse-width modulation signal to zero (i.e., blocking the first pulse-width modulation signal). At this point, it can be assumed that the controller 31 does not transmit a voltage signal, or a low voltage signal, to the gate of the third transistor 333. The third transistor 333 is turned off, de-energizing the brake coil 51, and the brake coil 51 ceases operation. This reduces the risk of damage to the brake coil 51 due to excessive current flow and increases the service life of the brake coil 51.

[0092] On this basis, the controller 31 further includes a first counter. Each time the first comparator 336 transmits the first cutoff signal to the controller 31, the value of the first counter is incremented by one. When the value of the first counter is greater than a first counting threshold, the controller 31 sets the duty cycle of the first pulse width modulation signal to 0. The first counting threshold can be set according to actual conditions. For example, the first counting threshold is 3.

[0093] When blocking the first PWM signal, in addition to adjusting the duty cycle to 0 as described above, when the first comparator 336 determines that the first voltage value is greater than the first reference voltage value, the first comparator 336 may also cause the first PWM signal transmitted by the controller 31 to flow to the ground terminal. For example, the first comparator 336 controls the ground switch of the controller 31 to close, so that the third transistor 333 cannot receive the first PWM signal and is turned off, thereby blocking the first PWM signal.

[0094] Therefore, when the first comparator 336 transmits the first cutoff signal to the controller 31, the duty cycle of the first pulse width modulation signal of the controller 31 is 0, and the first comparator 336 makes the first pulse width modulation signal transmitted by the controller 31 flow to the ground terminal. At least one of them takes effect, so that the third transistor 333 is cut off, the brake coil 51 loses power, the brake coil 51 stops working, and the brake 50 brakes the motor 20, thereby reducing the risk of safety accidents in the mobile robot.

[0095] If the first comparator 336 compares the first voltage value to be less than or equal to the first reference voltage value, it means that the voltage of the first sampling resistor 335 is not large, that is, the current in the branch where the first sampling resistor 335 is located is not large, and thus the brake coil 51 will not be damaged. In this case, the first comparator 336 transmits a first stabilization signal to the controller 31. The controller 31 receives the first stabilization signal and keeps the duty cycle of the first pulse width modulation signal unchanged.

[0096] In the case that the controller 31 includes the third control unit 313 and the fourth control unit 314 , the output terminal of the first comparator 336 is electrically connected to the third control unit 313 .

[0097] If the first voltage value is greater than the first reference voltage value, the first comparator 336 transmits a first cutoff signal to the third control unit 313. The third control unit 313 receives the first cutoff signal and sets the duty cycle of the first pulse width modulation signal to 0. In this way, the output end of the second AND circuit 334 transmits a low voltage signal to the third transistor 333, and the third transistor 333 is turned off.

[0098] If the first voltage value is less than or equal to the first reference voltage value, the first comparator 336 transmits a first stabilization signal to the third control unit 313 . The third control unit 313 receives the first stabilization signal to keep the duty cycle of the first PWM signal unchanged.

[0099] In some embodiments, as shown in FIG2 , the motor driver 30 further includes a first diode 35. The anode of the first diode 35 is connected to the second end of the brake coil 51, and the cathode is connected to the first end of the brake coil 51. When the brake coil 51 is de-energized, an induced electromotive force is generated. A reverse high voltage is generated across the brake coil 51, and the first diode 35 is turned on. A path is formed between the brake coil 51 and the first diode 35, allowing the first diode 35 to release the magnetic field energy stored in the brake coil 51.

[0100] In some embodiments, as shown in Figure 2, the second transistor 341 is an N-type transistor. The controller 31 further includes a fifth control unit 315 and a sixth control unit 316. The first control unit 311 and the second control unit 312 may each include an MCU.

[0101] The fifth control unit 315 and the first control unit 311 may be the same control unit, and the sixth control unit 316 and the second control unit 312 may be the same control unit, so that resources can be saved.

[0102] The contactor coil control circuit 34 also includes a third AND circuit 342. At this time, the fifth control unit 315 and the sixth control unit 316 are electrically connected to the two input ends of the third AND circuit 342 respectively, and the output end of the third AND circuit 342 is electrically connected to the gate of the second transistor 341, thereby realizing the electrical connection between the controller 31 and the second transistor 341.

[0103] The output end of the third AND circuit 342 is electrically connected to the gate of the second transistor 341. Thus, the controller 31 uses the voltage signal transmitted to the third AND circuit 342 by the fifth control unit 315 and the sixth control unit 316 to control the voltage signal transmitted from the output end of the third AND circuit 342 to the gate of the second transistor 341, thereby controlling the conduction or cutoff of the second transistor 341.

[0104] For example, when the second transistor 341 is an N-type transistor, the third AND circuit 342 transmits a low voltage signal to the gate of the second transistor 341 to turn off the second transistor 341 , or transmits a high voltage signal to turn on the second transistor 341 .

[0105] A first input terminal of the third AND circuit 342 is electrically connected to the fifth control unit 315, and a second input terminal is electrically connected to the sixth control unit 316. The signal transmitted by the fifth control unit 315 to the third AND circuit 342 is the same as the signal transmitted by the sixth control unit 316 to the third AND circuit 342.

[0106] When the fifth control unit 315 transmits a high-voltage signal to the third AND circuit 342, and the sixth control unit 316 also transmits a high-voltage signal to the third AND circuit 342, the output terminal of the third AND circuit 342 transmits the high-voltage signal to the gate of the second transistor 341. Since the second transistor 341 is an N-type transistor, the high-voltage signal turns on the second transistor 341, energizing the contactor coil 41.

[0107] When the fifth control unit 315 transmits a low-voltage signal to the third AND circuit 342, and / or the sixth control unit 316 transmits a low-voltage signal to the third AND circuit 342, the output terminal of the third AND circuit 342 transmits a low-voltage signal to the gate of the second transistor 341. Because the first transistor 331 is an N-type transistor, the low-voltage signal turns off the second transistor 341, de-energizing the contactor coil 41, and the contactor 40 brakes the motor 20. This improves operational efficiency and provides more stable and reliable braking of the motor 20.

[0108] During signal transmission, noise, pulse jitter, a poor external battery environment, or other factors can cause signal corruption during transmission, resulting in bit errors. For example, if the signal transmitted by the controller 31 is a low-voltage signal (a low-voltage signal can turn off the second transistor 341), the signal is corrupted during transmission, and the signal received by the second transistor 341 is a high-voltage signal, which turns on the second transistor 341, causing the contactor coil 41 to lose power. The contactor 40 cannot brake the motor 20, resulting in the mobile robot being unable to stop in time and having low safety and reliability.

[0109] Thus, if the mobile robot is about to collide with a staff member or an object, the fifth control unit 315 and the sixth control unit 316 respectively transmit a low-voltage signal to the third AND circuit 342. During the signal transmission process, at least one of the low-voltage signal transmitted by the fifth control unit 315 to the third AND circuit 342 and the low-voltage signal transmitted by the sixth control unit 316 to the third AND circuit 342 does not change. The output end of the third AND circuit 342 transmits a low-voltage signal to the second transistor 341, which turns off. The contactor coil 41 loses power, the contactor coil 41 has no electromagnetic force, the normally closed contact of the contactor 40 opens, the motor 20 loses power and inertia, and the normally open contact of the contactor 40 closes, and the motor 20 generates a braking torque that prevents the motor 20 from rotating. Under the action of the braking torque, the speed of the motor 20 drops rapidly, and the mobile robot can stop moving in time, reducing the risk of safety accidents of the mobile robot and improving the safety and reliability of the mobile robot. The present disclosure adopts the second transistor 341 and the third AND circuit 342 to enable the motor 20 to brake in time, stop the mobile robot in time, and improve safety and reliability.

[0110] In some embodiments, as shown in FIG. 2 , the contactor coil control circuit 34 further includes a fourth transistor 343 .

[0111] The type of the fourth transistor 343 can be the same as the type of the aforementioned transistors, that is, the type of the fourth transistor 343 can be the same as the type of the first transistor 331, the second transistor 341, and the third transistor 333. For example, the first transistor 331, the second transistor 341, the third transistor 333, and the fourth transistor 343 are all N-type transistors.

[0112] The type of the fourth transistor 343 may also be different from the types of the aforementioned transistors. For example, the first transistor 331 , the second transistor 341 , and the third transistor 333 are all N-type transistors, and the fourth transistor 343 is a P-type transistor.

[0113] A first electrode of the fourth transistor 343 is electrically connected to the second end of the contactor coil 41 , and a second electrode of the fourth transistor 343 is grounded, thereby grounding the second end of the contactor coil 41 . A gate of the fourth transistor 343 is electrically connected to the controller 31 .

[0114] The controller 31 is further configured to control the on / off state of the fourth transistor 343. For example, when the fourth transistor 343 is an N-type transistor, the controller 31 transmits a low voltage signal to the gate of the fourth transistor 343 to turn off the fourth transistor 343, or transmits a high voltage signal to the gate of the fourth transistor 343 to turn on the fourth transistor 343.

[0115] When controlling the operation of the motor 20, the controller 31 transmits a second pulse-width modulation signal to the fourth transistor 343. The controller 31 changes the effective voltage across the contactor coil 41 by varying the duty cycle of the second pulse-width modulation signal, thereby matching the effective voltage across the contactor coil 41 with the rated voltage of the contactor coil 41 and improving the service life of the contactor coil 41.

[0116] In some embodiments, as shown in FIG2 , the fourth transistor 343 is an N-type transistor. The controller 31 further includes a seventh control unit 317 and an eighth control unit 318. The eighth control unit 318 and the fourth control unit 314 can be the same control unit to save resources.

[0117] The contactor coil control circuit 34 also includes a fourth AND circuit 344. At this time, the seventh control unit 317 and the eighth control unit 318 are electrically connected to the two input ends of the fourth AND circuit 344 respectively, and the output end of the fourth AND circuit 344 is electrically connected to the gate of the fourth transistor 343, thereby realizing the electrical connection between the controller 31 and the fourth transistor 343.

[0118] The output end of the fourth AND circuit 344 is electrically connected to the gate of the fourth transistor 343. The controller 31 uses the voltage signal transmitted to the fourth AND circuit 344 by the seventh control unit 317 and the eighth control unit 318 to control the voltage signal output by the fourth AND circuit 344, thereby controlling the conduction or cutoff of the fourth transistor 343.

[0119] For example, when the fourth transistor 343 is an N-type transistor, the seventh control unit 317 and the eighth control unit 318 both transmit a low voltage signal to the fourth AND circuit 344, so that the output end of the fourth AND circuit 344 outputs a low voltage signal, and the fourth AND circuit 344 transmits a low voltage signal to the gate of the fourth transistor 343, so that the fourth transistor 343 is cut off, or the seventh control unit 317 and the eighth control unit 318 both transmit a high voltage signal to the fourth AND circuit 344, so that the output end of the fourth AND circuit 344 outputs a high voltage signal, and the fourth AND circuit 344 transmits a high voltage signal to the gate of the fourth transistor 343, so that the fourth transistor 343 is turned on.

[0120] A first input terminal of the fourth AND circuit 344 is electrically connected to the seventh control unit 317 , and a second input terminal of the fourth AND circuit 344 is electrically connected to the eighth control unit 318 .

[0121] When the mobile robot is operating normally, the seventh control unit 317 transmits a second pulse width modulated signal to the fourth AND circuit 344. The seventh control unit 317 can change the effective voltage across the contactor coil 41 by changing the duty cycle of the second pulse width modulated signal, so that the effective voltage across the contactor coil 41 matches the rated voltage of the contactor coil 41. Because the pulse period of a pulse width modulated signal is generally short, the power-off time within a pulse period is even shorter. Therefore, the second pulse width modulated signal transmitted by the seventh control unit 317 to the fourth AND circuit 344 can be considered a high voltage signal.

[0122] The eighth control unit 318 is configured to control the signal outputted from the output terminal of the fourth AND circuit 344. When the third control unit 313 transmits a high-voltage signal to the second AND circuit 334, if the signal transmitted by the eighth control unit 318 to the fourth AND circuit 344 is a low-voltage signal within a pulse cycle, the signal outputted from the output terminal of the fourth AND circuit 344 is a low-voltage signal, and the fourth AND circuit 344 transmits the low-voltage signal to the gate of the fourth transistor 343, turning off the fourth transistor 343. If the signal transmitted by the eighth control unit 318 to the fourth AND circuit 344 is a high-voltage signal, the signal outputted from the output terminal of the fourth AND circuit 344 is a high-voltage signal, and the fourth AND circuit 344 transmits the high-voltage signal to the gate of the fourth transistor 343, turning on the fourth transistor 343.

[0123] If the mobile robot is about to hit a staff member or an object, the seventh control unit 317 and the eighth control unit 318 respectively transmit a low-voltage signal to the fourth AND circuit 344. During the signal transmission process, at least one of the low-voltage signal transmitted by the seventh control unit 317 to the fourth AND circuit 344 and the low-voltage signal transmitted by the eighth control unit 318 to the fourth AND circuit 344 does not change. The output end of the fourth AND circuit 344 transmits a low-voltage signal to the fourth transistor 343. The fourth transistor 343 is cut off, the contactor coil 41 has no electromagnetic force, the normally closed contact of the contactor 40 is disconnected, the motor 20 loses power and moves by inertia. At the same time, the normally open contact of the contactor 40 is closed, and the motor 20 generates a braking torque to prevent the motor 20 from rotating. Under the action of the braking torque, the speed of the motor 20 drops rapidly, and the mobile robot can stop moving in time, reducing the risk of safety accidents of the mobile robot and improving the safety and reliability of the mobile robot.

[0124] In some embodiments, as shown in FIG. 2 , the contactor coil control circuit 34 further includes a second sampling resistor 345 and a second comparator 346 .

[0125] One end of the second sampling resistor 345 is electrically connected to the second electrode of the fourth transistor 343 , and the other end of the second sampling resistor 345 is grounded, thereby achieving the grounding of the second electrode of the third transistor 333 .

[0126] The second sampling resistor 345 is used to collect a second voltage value of the branch where the contactor coil 41 is located.

[0127] The output terminal of the second comparator 346 is electrically connected to the controller 31, and the input terminal is connected to the second sampling resistor 345. The second comparator 346 is used to receive the second voltage value collected by the second sampling resistor 345 and determine the difference between the second voltage value and the second reference voltage value.

[0128] The second reference voltage value can be selected based on the rated voltage of the contactor coil 41, or can be set by the operator according to actual circumstances. The embodiments of the present disclosure do not specifically limit this. For example, the second reference voltage value can be less than the rated voltage of the contactor coil 41, for example, the second reference voltage value is 3V.

[0129] If the second comparator 346 compares the second voltage value to be greater than the second reference voltage value, it indicates that the voltage of the second sampling resistor 345 is larger, and the current flowing through the second sampling resistor 345 is larger, that is, the current in the branch where the second sampling resistor 345 is located is larger. Since the contactor coil 41 is a component in the branch where the second sampling resistor 345 is located, the current flowing through the contactor coil 41 is also larger, which may cause damage to the contactor coil 41. In this case, the second comparator 346 can transmit a second cutoff signal to the controller 31. The controller 31 receives the second cutoff signal and sets the duty cycle of the second pulse width modulation signal to 0. At this time, it can be considered that the controller 31 does not transmit a voltage signal or a low voltage signal to the gate of the fourth transistor 343. The fourth transistor 343 is turned off, the contactor coil 41 loses power, and the contactor coil 41 stops working. This can reduce the risk of damage caused by excessive current in the contactor coil 41 and increase the service life of the contactor coil 41.

[0130] If the second comparator 346 determines that the second voltage value is less than or equal to the second reference voltage value, it means that the voltage of the second sampling resistor 345 is not large, that is, the current in the branch where the second sampling resistor 345 is located is not large, and thus the contactor coil 41 will not be damaged. In this case, the second comparator 346 transmits a second stabilization signal to the controller 31. The controller 31 receives the second stabilization signal and keeps the duty cycle of the second pulse width modulation signal unchanged.

[0131] When the controller 31 includes a seventh control unit 317 and an eighth control unit 318, the output end of the second comparator 346 is electrically connected to the seventh control unit 317. If the second voltage value is greater than the second reference voltage value, the second comparator 346 transmits a second cutoff signal to the seventh control unit 317. The seventh control unit 317 receives the second cutoff signal, making the duty cycle of the second pulse width modulation signal 0. In this way, the output end of the fourth AND circuit 344 transmits a low voltage signal to the fourth transistor 343, and the fourth transistor 343 is cut off.

[0132] If the second voltage value is less than or equal to the second reference voltage value, the second comparator 346 transmits a second stabilization signal to the seventh control unit 317 . The seventh control unit 317 receives the second stabilization signal and keeps the duty cycle of the second PWM signal unchanged.

[0133] In some embodiments, as shown in FIG2 , the motor driver 30 further includes a second diode 36 , the anode of the second diode 36 being connected to the second end of the contactor coil 41, and the cathode being connected to the first end of the contactor coil 41. When the contactor coil 41 is de-energized, an induced electromotive force is generated, and a reverse high voltage is generated across the contactor coil 41. The second diode 36 then conducts, forming a path between the contactor coil 41 and the second diode 36 , allowing the second diode 36 to release the magnetic field energy stored in the contactor coil 41.

[0134] In some embodiments, as shown in Figure 3, the controller 31 includes a first processor 301 and a second processor 302. The first control unit 311, the third control unit 313, the fifth control unit 315, and the seventh control unit 317 are located in the first processor 301, while the second control unit 312, the fourth control unit 314, the sixth control unit 316, and the eighth control unit 318 are located in the second processor 302. When at least one of the first processor 301 and the second processor 302 is operational, the contactor coil control circuit 34 and the brake coil control circuit 33 can function properly, reducing the risk of safety accidents in the mobile robot and improving the safety level of the mobile robot.

[0135] In the embodiments of the present disclosure, the contactor braking and the holding brake braking are combined to improve the risk of a safety accident of the mobile robot caused by the failure of a single braking method. The transistor and the circuit are combined to enable the motor 20 to brake in time and the mobile robot to stop in time, thereby improving safety and reliability and reducing the risk of a safety accident of the mobile robot. The combination of the comparator and the controller can reduce the risk of a safety accident of the mobile robot caused by improper coil selection. At the same time, the combination of the comparator blocking the PWM signal and the controller changing the duty cycle of the PWM signal can also reduce the risk of a safety accident of the mobile robot. The combination of the first processor and the second processor can reduce the risk of a safety accident of the mobile robot caused by the easy failure of a single processor. In summary, the safety level of the mobile robot disclosed in the present disclosure is relatively high.

[0136] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0137] The above are only specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A motor control system, characterized in that: include: A motor driver, electrically connected to the motor and configured to control the operating state of the motor; a contactor connected in series between a power source and the motor driver and configured to brake the motor; A holding brake, electrically connected to the motor driver and cooperating with the motor, configured to brake the motor; Wherein, the motor driver is further configured to control the contactor to brake the motor, and control the brake to brake the motor.

2. The motor control system according to claim 1, characterized in that: The brake comprises a brake coil, and the contactor comprises a contactor coil; The motor driver comprises: a controller, electrically connected to the motor and configured to control the operating state of the motor; The brake coil control circuit comprises a first transistor, wherein a first electrode of the first transistor is electrically connected to a first voltage signal terminal, a second electrode is connected to a first end of the brake coil, and a gate is electrically connected to the controller; A contactor coil control circuit comprises a second transistor, wherein a first electrode of the second transistor is electrically connected to the first voltage signal terminal, a second electrode is electrically connected to the first end of the contactor coil, and a gate is electrically connected to the controller; The second end of the brake coil is grounded; the second end of the contactor coil is grounded; The controller is further configured to control the on or off state of the first transistor to control the holding brake to brake the motor, and to control the on or off state of the second transistor to control the contactor to brake the motor.

3. The motor control system according to claim 2, characterized in that: The first transistor is an N-type transistor or a P-type transistor, and the controller includes a first control unit and a second control unit; The brake coil control circuit further includes a first AND circuit, wherein an output end of the first AND circuit is electrically connected to the gate of the first transistor, a first input end is electrically connected to the first control unit, and a second input end is electrically connected to the second control unit; The signal transmitted by the first control unit to the first AND circuit is the same as the signal transmitted by the second control unit to the first AND circuit.

4. The motor control system according to claim 3, characterized in that: The brake coil control circuit further includes a third transistor, a first electrode of the third transistor is electrically connected to the second end of the brake coil, a second electrode of the third transistor is grounded, and a gate of the third transistor is electrically connected to the controller; The controller is further configured to transmit a first pulse width modulation signal to the third transistor and change a duty cycle of the first pulse width modulation signal.

5. The motor control system according to claim 4, characterized in that: The third transistor is an N-type transistor or a P-type transistor, and the controller includes a third control unit and a fourth control unit; The brake coil control circuit also includes: a second AND circuit, wherein an output terminal of the second AND circuit is electrically connected to the gate of the third transistor, a first input terminal is electrically connected to the third control unit, and a second input terminal is electrically connected to the fourth control unit; The third control unit is configured to transmit the first pulse width modulation signal to the second AND circuit and change the duty cycle of the first pulse width modulation signal, and the fourth control unit is configured to control the on or off of the third transistor.

6. The motor control system according to claim 4, characterized in that: The brake coil control circuit also includes: a first sampling resistor, one end of which is electrically connected to the second electrode of the third transistor, and the other end of which is grounded; A first comparator, wherein an output terminal of the first comparator is electrically connected to the controller, an input terminal of the first comparator is electrically connected to the first sampling resistor, and the comparator is configured to receive a first voltage value across the first sampling resistor and determine a magnitude between the first voltage value and a first reference voltage value; If the first voltage value is greater than the first reference voltage value, the first comparator transmits a first cutoff signal to the controller, and the controller receives the first cutoff signal to make the duty cycle of the first pulse width modulation signal 0; If the first voltage value is less than or equal to the first reference voltage value, the first comparator transmits a first stable signal to the controller, and the controller receives the first stable signal to keep the duty cycle of the first pulse width modulation signal unchanged.

7. The motor control system according to any one of claims 2 to 6, characterized in that: The second transistor is an N-type transistor or a P-type transistor, and the controller includes a fifth control unit and a sixth control unit; The contactor coil control circuit further includes a third AND circuit, wherein an output end of the third AND circuit is electrically connected to the gate of the second transistor, a first input end is electrically connected to the fifth control unit, and a second input end is electrically connected to the sixth control unit; The signal transmitted by the fifth control unit to the third AND circuit is the same as the signal transmitted by the sixth control unit to the third AND circuit.

8. The motor control system according to claim 7, characterized in that: The contactor coil control circuit further includes a fourth transistor, a first electrode of the fourth transistor is electrically connected to the second end of the contactor coil, a second electrode of the fourth transistor is grounded, and a gate is electrically connected to the controller; The controller is configured to transmit a second pulse width modulation signal to the fourth transistor and change a duty cycle of the second pulse width modulation signal.

9. The motor control system according to claim 8, characterized in that: The fourth transistor is an N-type transistor or a P-type transistor, and the controller includes a seventh control unit and an eighth control unit; The contactor coil control circuit further includes a fourth AND circuit, wherein an output end of the fourth AND circuit is electrically connected to the gate of the fourth transistor, a first input end is electrically connected to the seventh control unit, and a second input end is electrically connected to the eighth control unit; The seventh control unit is configured to transmit a second pulse width modulation signal to the fourth AND circuit and change the duty cycle of the second pulse width modulation signal, and the eighth control unit is configured to turn on or off the fourth transistor.

10. The motor control system according to claim 8, characterized in that: The contactor coil control circuit also includes: a second sampling resistor, one end of the second sampling resistor being electrically connected to the second electrode of the fourth transistor, and the other end of the second sampling resistor being grounded; A second comparator, wherein an input end of the second comparator is electrically connected to the second sampling resistor, an output end of the second comparator is electrically connected to the controller, and is configured to receive a second voltage value across the second sampling resistor and determine a magnitude between the second voltage value and a second reference voltage value; If the second voltage value is greater than the second reference voltage value, the second comparator transmits a second cutoff signal to the controller, and the controller receives the second cutoff signal to make the duty cycle of the second pulse width modulation signal 0; If the second voltage value is less than or equal to the second reference voltage value, the second comparator transmits a second stable signal to the controller, and the controller receives the second stable signal to keep the duty cycle of the second pulse width modulation signal unchanged.

11. According to the motor control system of claim 9, the controller also includes a first processor and a second processor, the first control unit, the third control unit, the fifth control unit and the seventh control unit are located in the first processor, and the second control unit, the fourth control unit, the sixth control unit and the eighth control unit are located in the second processor.

12. A mobile robot, characterized in that: It comprises a motor control system as claimed in any one of claims 1 to 11.

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