A short-term self-locking protection circuit for robot joints

Abstract

This utility model relates to a short-time self-locking protection circuit for robot joints, including a three-phase drive circuit for a motor and a short-time self-locking protection circuit. The short-time self-locking protection circuit includes capacitor C1, capacitor C2, resistor R1, diode D6, optocoupler U1, and three parallel MOSFETs Q1, Q2, and Q3. One end of capacitor C1 is connected to the negative terminal of diode D6, capacitor C2, and resistor R1; the positive terminal of diode D6 is connected to power supply Vcc_2; and the other end of capacitor C1 is connected to the other end of capacitor C2 and ground. This utility model has the following advantages: 1. Reduced cost: avoids the use of high-cost mechanical brake devices. 2. Improved reliability: reduces the use of mechanical parts, lowering the risk of failure due to mechanical wear. 3. Facilitates handling and calibration: in the event of power failure, the motor can return to a non-self-locking state after a period of time, facilitating handling and attitude calibration.

Description

Technical Field

[0001] This utility model relates to the field of motion control of robot joint actuators, specifically a protection circuit for briefly locking joint motors to prevent further damage when a robot loses power. Background Technology

[0002] In robotics, when a robot suddenly loses power, the joint motors may continue to run due to inertia, causing the robot to fall or its joints to continue moving. This could damage the robot itself and potentially injure nearby people or objects. Current technologies typically use mechanical brakes or relay circuits to lock the motors, but these methods suffer from high costs, limited lifespan of mechanical brakes, and the inconvenience of handling and attitude calibration caused by relay circuits keeping the motor in a locked state for extended periods. Utility Model Content

[0003] In view of the problems existing in the prior art, this utility model proposes a new circuit design scheme. This scheme can actively lock the motor for a short time when the robot loses power, preventing it from rotating, thereby effectively reducing the damage to the robot body and the surrounding environment.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A short-time self-locking protection circuit for robot joints includes a three-phase drive circuit for a motor and a short-time self-locking protection circuit.

[0006] The short-time self-locking protection circuit includes capacitor C1, capacitor C2, resistor R1, diode D6, optocoupler U1, and three parallel MOSFETs Q1, Q2, and Q3;

[0007] One end of capacitor C1 is connected to the negative terminal of diode D6, capacitor C2 and resistor R1, the positive terminal of diode D6 is connected to power supply Vcc_2, and the other end of capacitor C1 is connected to the other end of capacitor C2 and ground.

[0008] The other end of the resistor R1 is connected to the gate of MOSFET Q1, the gate of MOSFET Q2, and the gate of MOSFET Q3.

[0009] The input pin 1 of the optocoupler U1 is connected to resistor R2, and the other end of resistor R2 is connected to the signal line of the power monitoring module of the robot system. The output pin of the optocoupler U1 is connected to the gate of MOSFET Q1, the gate of MOSFET Q2, and the gate of MOSFET Q3. The drains of MOSFET Q1, Q2, and Q3 are respectively connected to the three-phase windings U, V, and W of motor M. The sources of MOSFET Q1, Q2, and Q3 are all grounded.

[0010] As a further technical solution of this utility model: when the robot system is working normally, the power monitoring module signal line signal is at a high level, and when the robot system loses power abnormally, the signal line signal is at a low level.

[0011] As a further technical solution of this utility model: the three-phase drive circuit of the motor includes MOSFETs Q4, Q5, Q6, Q7, Q8, and Q9. The drain of MOSFET Q4 is connected to the drains of MOSFETs Q6 and Q8, capacitor C3, and power supply VCC_BUS. The other end of capacitor C3 is grounded. The source of MOSFET Q4 is connected to the drain of MOSFET Q5. The source of MOSFET Q6 is connected to the drain of MOSFET Q7. The source of MOSFET Q8 is connected to the drain of MOSFET Q9. The source of MOSFET Q5 is connected to resistor R3, the other end of resistor R3 is grounded. The source of MOSFET Q7 is connected to resistor R4, the other end of resistor R4 is grounded. The source of MOSFET Q9 is connected to resistor R5, the other end of resistor R5 is grounded.

[0012] As a further technical solution of this utility model: the values ​​of capacitor C1, capacitor C2 and resistor R satisfy the following: the discharge time range is 10 seconds to 5 minutes.

[0013] As a further technical solution of this utility model: the optocoupler U1 is a high-speed optocoupler, model PC817.

[0014] As a further technical solution of this utility model: the MOS transistors Q1, Q2, and Q3 are all N-channel enhancement-type MOS transistors, model number IRF540.

[0015] As a further technical solution of this utility model: the diode D6 is a Schottky diode, model number 1N5819N.

[0016] As a further technical solution of this utility model: the power supply Vcc_2 is an independent backup power supply or a redundant power supply module of the main power supply of the robot system.

[0017] As a further technical solution of this utility model: the capacitance of capacitors C1 and C2 is 100μF to 1000μF, and the withstand voltage is 25V to 50V.

[0018] As a further technical solution of this utility model: the circuit is suitable for the joint drive system of service robots, industrial robots or collaborative robots.

[0019] The technical effects and advantages provided by this utility model in the above technical solution are as follows:

[0020] 1. Reduced costs: Avoids the use of high-cost mechanical brake devices.

[0021] 2. Improved reliability: Reduced use of mechanical parts lowers the risk of failure due to mechanical wear.

[0022] 3. Easy to handle and calibrate: In the event of power failure, the motor can return to a non-locking state after a period of time, which facilitates handling and attitude calibration. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This invention relates to a short-time self-locking protection circuit diagram for a motor in a robot joint short-time self-locking protection circuit.

[0025] Figure 2 This invention relates to a three-phase drive circuit diagram of a motor for a robot joint short-time self-locking protection circuit. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] It should be noted that the terms "vertical," "horizontal," "up," "down," "left," "right," and similar expressions used in this article are for illustrative purposes only and do not represent the only possible implementation.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] Example 1:

[0030] This utility model provides, for example Figure 1 The drawing shown specifically illustrates a short-term self-locking protection circuit for a robot joint, comprising a three-phase drive circuit for the motor and a short-term self-locking protection circuit.

[0031] The short-time self-locking protection circuit includes capacitor C1, capacitor C2, resistor R1, diode D6, optocoupler U1, and three parallel MOSFETs Q1, Q2, and Q3;

[0032] One end of capacitor C1 is connected to the negative terminal of diode D6, capacitor C2 and resistor R1, the positive terminal of diode D6 is connected to power supply Vcc_2, and the other end of capacitor C1 is connected to the other end of capacitor C2 and ground.

[0033] The other end of the resistor R1 is connected to the gate of MOSFET Q1, the gate of MOSFET Q2, and the gate of MOSFET Q3.

[0034] The input pin 1 of the optocoupler U1 is connected to resistor R2, and the other end of resistor R2 is connected to the signal line of the power monitoring module of the robot system. The output pin of the optocoupler U1 is connected to the gate of MOSFET Q1, the gate of MOSFET Q2, and the gate of MOSFET Q3. The drains of MOSFET Q1, Q2, and Q3 are respectively connected to the three-phase windings U, V, and W of motor M. The sources of MOSFET Q1, Q2, and Q3 are all grounded.

[0035] Example 2:

[0036] Based on Example 1, when the robot system is working normally, the power monitoring module signal line signal is at a high level, and when the robot system loses power abnormally, the signal line signal is at a low level.

[0037] Example 3:

[0038] Based on Embodiment 1, the three-phase drive circuit of the motor includes MOSFETs Q4, Q5, Q6, Q7, Q8, and Q9. The drain of MOSFET Q4 is connected to the drains of MOSFETs Q6 and Q8, capacitor C3, and power supply VCC_BUS. The other end of capacitor C3 is grounded. The source of MOSFET Q4 is connected to the drain of MOSFET Q5, the source of MOSFET Q6 is connected to the drain of MOSFET Q7, and the source of MOSFET Q8 is connected to the drain of MOSFET Q9. The source of MOSFET Q5 is connected to resistor R3, with the other end of resistor R3 grounded. The source of MOSFET Q7 is connected to resistor R4, with the other end of resistor R4 grounded. The source of MOSFET Q9 is connected to resistor R5, with the other end of resistor R5 grounded.

[0039] Example 4:

[0040] Based on Example 1, the values ​​of capacitor C1, capacitor C2 and resistor R are such that the discharge time ranges from 10 seconds to 5 minutes.

[0041] Example 5:

[0042] Based on Example 1, the optocoupler U1 is a high-speed optocoupler, model PC817. MOSFETs Q1, Q2, and Q3 are all N-channel enhancement-mode MOSFETs, model IRF540. Diode D6 is a Schottky diode, model 1N5819N. Power supply Vcc_2 is an independent backup power supply for the robot system or a redundant power supply module for the main power supply. Capacitors C1 and C2 have capacitance values ​​from 100μF to 1000μF and voltage ratings from 25V to 50V.

[0043] The circuit design is suitable for joint drive systems of service robots, industrial robots, or collaborative robots.

[0044] Working principle: Normal operating state: When the robot system is working normally, the signal is at a high voltage, the optocoupler is on, and the three MOSFETs are not on, so the self-locking effect is not achieved. At the same time, Vcc_2 charges capacitors C1 and C2 through diode D6.

[0045] Abnormal Power Loss State: When the robot experiences an abnormal power loss, Vcc_2 also loses power. At this time, capacitors C1 and C2 charge the three MOSFETs through resistor R1, causing them to conduct. Simultaneously, the three phases UVW of the motor are connected together, forming a short circuit, thus achieving a self-locking effect. Due to the inherent losses of capacitors C1 and C2 and the driving losses of the MOSFETs, the capacitors will discharge completely after a period of time, and the motor will return to a non-locking state. This allows the robot to tip over after an abnormal power loss, reducing the possibility of self-injury and minimizing potential damage to people or other objects.

[0046] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

[0047] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment have been appropriately combined to form other embodiments that are easy for those skilled in the art to understand.

Claims

1. A short-time self-locking protection circuit for robot joints, comprising a three-phase drive circuit for a motor and a short-time self-locking protection circuit. Its characteristics are: The short-time self-locking protection circuit includes capacitor C1, capacitor C2, resistor R1, diode D6, optocoupler U1, and three parallel MOSFETs Q1, Q2, and Q3; One end of capacitor C1 is connected to the negative terminal of diode D6, capacitor C2 and resistor R1, the positive terminal of diode D6 is connected to power supply Vcc_2, and the other end of capacitor C1 is connected to the other end of capacitor C2 and ground. The other end of the resistor R1 is connected to the gate of MOSFET Q1, the gate of MOSFET Q2, and the gate of MOSFET Q3. The input pin 1 of the optocoupler U1 is connected to resistor R2, and the other end of resistor R2 is connected to the signal line of the power monitoring module of the robot system. The output pin of the optocoupler U1 is connected to the gate of MOSFET Q1, the gate of MOSFET Q2, and the gate of MOSFET Q3. The drains of MOSFET Q1, Q2, and Q3 are respectively connected to the three-phase windings U, V, and W of motor M. The sources of MOSFET Q1, Q2, and Q3 are all grounded.

2. The robot joint short-time self-locking protection circuit according to claim 1, characterized in that: When the robot system is working normally, the power monitoring module signal line is at a high level; when the robot system loses power abnormally, the signal line is at a low level.

3. The robot joint short-time self-locking protection circuit according to claim 1, characterized in that: The three-phase drive circuit of the motor includes MOSFETs Q4, Q5, Q6, Q7, Q8, and Q9. The drain of MOSFET Q4 is connected to the drains of MOSFETs Q6 and Q8, capacitor C3, and power supply VCC_BUS. The other end of capacitor C3 is grounded. The source of MOSFET Q4 is connected to the drain of MOSFET Q5, the source of MOSFET Q6 is connected to the drain of MOSFET Q7, and the source of MOSFET Q8 is connected to the drain of MOSFET Q9. The source of MOSFET Q5 is connected to resistor R3, and the other end of resistor R3 is grounded. The source of MOSFET Q7 is connected to resistor R4, and the other end of resistor R4 is grounded. The source of MOSFET Q9 is connected to resistor R5, and the other end of resistor R5 is grounded.

4. The robot joint short-time self-locking protection circuit according to claim 1, characterized in that: The values ​​of capacitor C1, capacitor C2, and resistor R are selected to satisfy the following condition: the discharge time range is 10 seconds to 5 minutes.

5. The robot joint short-time self-locking protection circuit according to claim 1, characterized in that: The optocoupler U1 is a high-speed optocoupler, model PC817.

6. The robot joint short-time self-locking protection circuit according to claim 1, characterized in that: The MOSFETs Q1, Q2, and Q3 are all N-channel enhancement-type MOSFETs, model IRF540.

7. The robot joint short-time self-locking protection circuit according to claim 1, characterized in that: The diode D6 is a Schottky diode, model number 1N5819N.

8. The robot joint short-time self-locking protection circuit according to claim 1, characterized in that: The power supply Vcc_2 is an independent backup power supply or a redundant power supply module of the main power supply for the robot system.

9. A short-term self-locking protection circuit for robot joints according to claim 1, characterized in that: The capacitance values ​​of capacitors C1 and C2 are from 100μF to 1000μF, and the voltage rating is from 25V to 50V.

10. A robot joint short-time self-locking protection circuit according to claim 1, characterized in that: The circuit is suitable for joint drive systems of service robots, industrial robots, or collaborative robots.

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