Excitation band-type brake control circuit and mechanical arm

Abstract

The invention discloses an excitation band-type brake control circuit and a mechanical arm. The excitation band-type brake control circuit comprises a power conversion control module, a power enable control module, an adjustable output voltage feedback resistor and a delay module. The power conversion control module is used for generating a direct-current power supply to supply power to the excitation band-type brake coil; the power supply enabling control module is connected with the mechanical arm MCU and is used for controlling the working state of the power supply switching control module according to an output signal of the mechanical arm MCU; the adjustable output voltage feedback resistor is used for adjusting the power supply voltage of the excitation band-type brake coil according to the resistance change; and the delay module is used for adjusting the resistance of the adjustable output voltage feedback resistor according to the output signal of the mechanical arm MCU. The excitation band-type brake has the advantages that power is supplied to the excitation band-type brake in a direct-current power supply mode, on one hand, the power supply requirement of an excitation band-type brake coil is met, and on the other hand, the problems that switching loss is caused by a current PWM voltage regulation mode and EMC radiation exceeds the standard due to an alternating power source are solved.

Description

Technical Field

[0001] The present application relates to the technical field of robotic arms, and in particular to an excitation brake control circuit and a robotic arm. Background Art

[0002] In the existing robotic arm motion control system, the excitation brake coil release power supply control circuit uses a 24V DC power supply to activate the excitation brake coil release. After maintaining for 200ms, the MOS tube is controlled to output an alternating power supply through a PWM signal. By controlling the PWM duty cycle, the effective value of the alternating power supply is about 7V, which is used to keep the excitation brake coil in a released state and reduce the heat loss of the excitation brake coil. However, the disadvantage of this power supply method for releasing the excitation brake is that the MOS tube switch loss is large, and the EMC radiation problem caused by the alternating power supply also brings difficult-to-eradicate negative test results to the product, affecting the application of the robotic arm. Summary of the invention

[0003] The present application provides an excitation brake control circuit and a robotic arm, which have the advantage of using a DC power supply to power the excitation brake. On the one hand, it meets the power supply requirements of the excitation brake coil, and on the other hand, it solves the switching loss caused by the current PWM voltage regulation method and the EMC radiation exceeding the standard caused by the alternating power supply.

[0004] The technical solution of this application is as follows: On the one hand, the present application provides an excitation brake control circuit, including: A power conversion control module is used to generate a DC power supply to supply power to the excitation brake coil; A power enabling control module is connected to the robot arm MCU and is used to control the working state of the power conversion control module according to the output signal of the robot arm MCU; The adjustable output voltage feedback resistor is arranged between the excitation brake coil and the power conversion control module, and is used to adjust the supply voltage of the excitation brake coil according to the resistance change; and a delay module for adjusting the resistance of the adjustable output voltage feedback resistor according to the output signal of the robot arm MCU.

[0005] Furthermore, the power enable control module outputs a low voltage when the robot arm MCU output signal Power_Enable is at a low level, and the power conversion control module is in a closed state; the power enable control module outputs a high voltage when the robot arm MCU output signal Power_Enable is at a high level, and the power conversion control module is in an enabled state.

[0006] Furthermore, the adjustable output voltage feedback resistor has two resistance states, wherein, in the first resistance state, the output voltage of the power conversion control module is divided to 24V to power the excitation brake coil, and in the second resistance state, the output voltage of the power conversion control module is divided to 7V to power the excitation brake coil.

[0007] Furthermore, the delay module is connected to the power enable control module, and when the power enable control module outputs a high voltage, the adjustable output voltage feedback resistor is controlled to switch from a first resistance state to a second resistance state after a delay period.

[0008] Furthermore, the power conversion control module includes a Buck switch buck circuit consisting of a buck conversion chip U1, a freewheeling diode D1, a power energy storage inductor L1 and an energy storage capacitor C6, and the U1 enable pin EN is connected to the power enable control module.

[0009] Furthermore, the power enable control module includes MOS tubes Q2, Q3 and power supply Power_IN2, MOS tubes Q2, Q3 are connected in parallel between power supply Power_IN2 and ground, the base of MOS tube Q3 is connected to the robot arm MCU output signal Power_Enable, the base of MOS tube Q2 is connected to the high-voltage side of MOS tube Q3, MOS tube Q2 is grounded through resistor R9, and the output initial state of the power enable control module is that resistor R9 is pulled down to a low level, so that the initial state of the power conversion control module is closed.

[0010] Furthermore, the adjustable output voltage feedback resistor includes resistors R1 and R5 connected in series, and resistor R1 is connected in parallel with resistor R2 through MOS tube Q1. When MOS tube Q1 is turned on, resistors R1 and R2 are connected in parallel and in series with resistor R5, and the base of MOS tube Q1 is connected to the delay mode.

[0011] Furthermore, the delay module includes a 120ms delay chip. When the power enable control module outputs a high voltage, the delay module delays 120ms to output a high level to the MOS tube Q1 to turn on the MOS tube Q1.

[0012] Furthermore, it also includes a manual dial switch, which is connected to the power conversion control module and is used to manually control the power conversion control module to switch from a closed state to an enabled state.

[0013] On the other hand, the present application provides a robotic arm, including a robotic arm MCU, an excitation brake and the excitation brake control circuit as described above, the excitation brake coil is powered by the excitation brake control circuit, the robotic arm MCU is used to detect the working status of the robotic arm, and when an abnormality is detected, controls the excitation brake control circuit to cut off power supply and control the excitation brake to be in a locked state.

[0014] In summary, the beneficial effects of this application are: 1. The excitation brake control circuit of the present application is based on a DC power conversion method of delay control adjustment resistor voltage division method, which is used to excite the excitation brake coil to release and maintain the release state at low voltage; on the one hand, it meets the power supply requirements of the excitation brake coil, and on the other hand, it also solves the switching loss caused by the current PWM voltage regulation method and the EMC radiation exceeding the standard caused by the alternating power supply; 2. The excitation brake control circuit of the present application also uses a power conversion power supply mode, has a strong load capacity, can release the excitation brake coils of multiple joints at the same time, and has a good working synchronization effect; 3. When the excitation brake control circuit of the present application is used in a robot arm and connected to the robot arm MCU, it can reliably and stably follow the release and locking of the control system and has high working stability; 4. When the robotic arm in this application is used for medical equipment, it can pass the EMC radiation medical test index because the problem of excessive EMC radiation is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the principle of the excitation brake power supply control circuit in one embodiment of the present application; Figure 2 This is the design circuit of the excitation brake power supply control circuit in one embodiment of the present application. DETAILED DESCRIPTION

[0016] The specific implementation of the present application is described in detail below with reference to the accompanying drawings.

[0017] Embodiment 1: A field brake control circuit, referring to Figure 1 , including a power conversion control module, a power enable control module, an adjustable output voltage feedback resistor, a delay module and a brake coil.

[0018] The power conversion control module is used to generate a DC power supply to supply power to the excitation brake coil.

[0019] The power enable control module is connected to the robot arm MCU and is used to control the working state of the power conversion control module according to the output signal of the robot arm MCU. Specifically, the power enable control module outputs a low voltage when the robot arm MCU output signal Power_Enable is at a low level, and the power conversion control module is in a closed state; the power enable control module outputs a high voltage when the robot arm MCU output signal Power_Enable is at a high level, and the power conversion control module is in an enabled state.

[0020] The adjustable output voltage feedback resistor is arranged between the excitation brake coil and the power conversion control module, and is used to adjust the supply voltage of the excitation brake coil according to the resistance change. The adjustable output voltage feedback resistor has two resistance states, wherein in the first resistance state, the output voltage of the power conversion control module is divided to 24V to supply power to the excitation brake coil, and in the second resistance state, the output voltage of the power conversion control module is divided to 7V to supply power to the excitation brake coil.

[0021] The delay module is used to adjust the resistance of the adjustable output voltage feedback resistor according to the output signal of the robot arm MCU. The delay module is connected to the power enable control module, and when the power enable control module outputs a high voltage, the adjustable output voltage feedback resistor is controlled to change from a first resistance state to a second resistance state after a delay period.

[0022] refer to Figure 2 In this embodiment, the power conversion control module includes a buck switch buck circuit composed of a buck conversion chip U1, a freewheeling diode D1, a power energy storage inductor L1 and an energy storage capacitor C6, which is used to step down the input power supply Power_IN1 and output it. The U1 enable pin EN is connected to the power enable control module. The RT / CLK pin of U1 is connected to a resistor R3, and R3 is used to set the switching frequency of the switching power supply. C9 is used to set the startup time after the power conversion circuit is enabled, R4, C10, C11 are switching noise compensation components, and C5 is a bootstrap capacitor.

[0023] The power enable control module includes MOS tubes Q2, Q3 and power supply Power_IN2. MOS tubes Q2 and Q3 are connected in parallel between power supply Power_IN2 and ground. The base of MOS tube Q3 is connected to the robot arm MCU output signal Power_Enable. The base of MOS tube Q2 is connected to the high-voltage side of MOS tube Q3. MOS tube Q2 is grounded through resistor R9. The output initial state of the power enable control module is that resistor R9 is pulled down to a low level, so that the initial state of the power conversion control module is closed.

[0024] The adjustable output voltage feedback resistor includes resistors R1 and R5 connected in series. The resistor R1 is connected in parallel with the resistor R2 through the MOS tube Q1. When the MOS tube Q1 is turned on, the resistors R1 and R2 are connected in parallel and then connected in series with the resistor R5. The base of the MOS tube Q1 is connected to the delay mode.

[0025] The delay module includes a 120ms delay chip. When the power enable control module outputs a high voltage, the delay module delays 120ms to output a high level to the MOS tube Q1 to turn on the MOS tube Q1.

[0026] A manual dial switch is also included, and the manual dial switch is connected to the power conversion control module, and is used to manually control the power conversion control module to switch from an off state to an enabled state. Specifically, in this embodiment, the manual dial switch is connected in series between the power supply Power_IN2 and the U1 enable pin EN. The manual dial switch is a single-pole double-throw switch.

[0027] When the MCU's IO output signal Power_Enable is at a low level, the enable pin EN of U1 is connected to the ground, and the power conversion control module is in the off state; when the Power_Enable signal is at a high level, the enable pin EN of U1 is connected to the power supply Power_IN2, and the power conversion control module enters the enabled state. At this time, the adjustable output voltage feedback resistor is divided by R1 and R5, and a 24V power supply is output, and the excitation brake coil is activated and released.

[0028] Power_IN2 is closed through Q2 and outputs a high level after a 120ms delay, meeting the Q1 switch closing condition. At this time, the adjustable output voltage feedback resistor is connected in parallel with R1 and R2 and then divided by R5 to output 7V. The excitation brake coil is powered by this voltage to maintain a low-loss release state.

[0029] The single-pole double-throw manual dial switch is used to manually enable the power conversion circuit and release the excitation brake coil.

[0030] The excitation brake control circuit of this embodiment is based on the DC power switching method to realize the 24V DC power supply to activate the excitation brake release. After a delay of 120ms, it switches to a 7V DC power supply to keep the brake coil in the released state. When the MCU detects an abnormal situation, the MCU will immediately set the Power_Enable signal to a low level, cut off the output of the power conversion circuit, and the brake will immediately lock to prevent the robot arm from falling abnormally.

[0031] Embodiment 2: A robotic arm comprises a robotic arm MCU, an excitation brake and the excitation brake control circuit as described above, wherein the excitation brake coil is powered by the excitation brake control circuit, the robotic arm MCU is used to detect the working status of the robotic arm, and when an abnormality is detected, such as short circuit, overload, overvoltage, overheating, emergency stop and other abnormal movement of the robotic arm, the excitation brake control circuit is controlled to cut off the power supply and control the excitation brake to be in a locked state.

[0032] The above is only a preferred implementation of the present application. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present application, and these all fall within the scope of protection of the present application.

Claims

1. An excitation brake control circuit, characterized in that: include: A power conversion control module is used to generate a DC power supply to supply power to the excitation brake coil; A power enabling control module is connected to the robot arm MCU and is used to control the working state of the power conversion control module according to the output signal of the robot arm MCU; The adjustable output voltage feedback resistor is arranged between the excitation brake coil and the power conversion control module, and is used to adjust the supply voltage of the excitation brake coil according to the resistance change; and a delay module for adjusting the resistance of the adjustable output voltage feedback resistor according to the output signal of the robot arm MCU.

2. The excitation brake control circuit according to claim 1, characterized in that: The power enable control module outputs a low voltage when the robot arm MCU output signal Power_Enable is at a low level, and the power conversion control module is in a closed state; the power enable control module outputs a high voltage when the robot arm MCU output signal Power_Enable is at a high level, and the power conversion control module is in an enabled state.

3. The excitation brake control circuit according to claim 1, characterized in that: The adjustable output voltage feedback resistor has two resistance states, wherein in the first resistance state, the output voltage of the power conversion control module is divided to 24V to power the excitation brake coil, and in the second resistance state, the output voltage of the power conversion control module is divided to 7V to power the excitation brake coil.

4. The excitation brake control circuit according to claim 3, characterized in that: The delay module is connected to the power enable control module, and when the power enable control module outputs a high voltage, the adjustable output voltage feedback resistor is controlled to change from a first resistance state to a second resistance state after a delay period.

5. The excitation brake control circuit according to claim 1, characterized in that: The power conversion control module includes a Buck switch buck circuit composed of a buck conversion chip U1, a freewheeling diode D1, a power energy storage inductor L1 and an energy storage capacitor C6, and the U1 enable pin EN is connected to the power enable control module.

6. The excitation brake control circuit according to claim 1, characterized in that: The power enable control module includes MOS tubes Q2, Q3 and power supply Power_IN2. MOS tubes Q2 and Q3 are connected in parallel between power supply Power_IN2 and ground. The base of MOS tube Q3 is connected to the robot arm MCU output signal Power_Enable. The base of MOS tube Q2 is connected to the high-voltage side of MOS tube Q3. MOS tube Q2 is grounded through resistor R9. The output initial state of the power enable control module is that resistor R9 is pulled down to a low level, so that the initial state of the power conversion control module is closed.

7. The excitation brake control circuit according to claim 1, characterized in that: The adjustable output voltage feedback resistor includes resistors R1 and R5 connected in series. The resistor R1 is connected in parallel with the resistor R2 through the MOS tube Q1. When the MOS tube Q1 is turned on, the resistors R1 and R2 are connected in parallel and then connected in series with the resistor R5. The base of the MOS tube Q1 is connected to the delay mode.

8. The excitation brake control circuit according to claim 7, characterized in that: The delay module includes a 120ms delay chip. When the power enable control module outputs a high voltage, the delay module delays 120ms to output a high level to the MOS tube Q1 to turn on the MOS tube Q1.

9. The excitation brake control circuit according to any one of claims 1 to 8, characterized in that: It also includes a manual dial switch, which is connected to the power conversion control module and is used for manually controlling the power conversion control module to switch from a closed state to an enabled state.

10. A robotic arm, characterized in that: It includes a robotic arm MCU, an excitation brake and an excitation brake control circuit as described in any one of claims 1 to 9, the excitation brake coil is powered by the excitation brake control circuit, the robotic arm MCU is used to detect the working status of the robotic arm, and when an abnormality is detected, controls the excitation brake control circuit to cut off power supply to control the excitation brake to be in a locked state.

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