Robot power-off protection system and device and storage medium

Abstract

The invention discloses a robot power-off protection system and device and a storage medium, and relates to the field of robots, a power supply provides normal working voltage for a control cabinet, and a collaborative robot body receives a control instruction output by the control cabinet and executes corresponding control operation; the power failure detection module collects the output voltage of the control cabinet; the discharge output of the discharge module is connected to the control cabinet; when the output voltage collected by the power failure detection module is smaller than a voltage threshold value, a discharge trigger signal is sent to the discharge module, the discharge module continues to supply power to the control cabinet based on the trigger signal, and the control cabinet sends a motion compensation instruction to the collaborative robot to control a target joint of the collaborative robot to be lifted in the reverse direction of gravity. According to the scheme, the robot can be reversely lifted in the power-off process according to the direction of the current gravity borne by the robot, a temporary power source is provided for the control cabinet in the power-off process of the control cabinet, the voltage falling curve of the control cabinet is slowed down, and the time that the control cabinet falls to the lowest control voltage from the normal voltage is prolonged.

Description

Technical Field

[0001] The present application relates to the field of robots, and in particular to a collaborative robot power-off protection method, device, equipment and storage medium. Background Art

[0002] Collaborative robots are different from industrial robots. Collaborative robots are lightweight, safe, and flexible. They can interact and collaborate with operators at close range in a common workspace to assist operators in completing various tasks. The safety of collaborative robots is mainly reflected in their perception of the external environment. In particular, when they sense an external collision, they can trigger a collision stop in a timely manner, effectively avoiding or reducing the damage to operators and workpieces caused by accidents such as collisions. Based on this feature, collaborative robots also have many application scenarios in the medical and health care fields. In the medical and health care fields, taking the massage scenario as an example, when a collaborative robot encounters an unexpected power failure during use (for example, an unexpected power failure of the power socket or improper use that causes the robot to lose power, etc.), due to gravity, when the robot closes the brake of the joint motor, the robot will produce a displacement of a distance along the direction of gravity, which will easily bring a bad experience to the user and also bring safety hazards.

[0003] In the related art, two solutions are usually adopted: rapid braking and redundant design. Rapid braking is to quickly brake the motor in the event of an unexpected power outage through a mechanical or electromagnetic structure, so as to minimize the descent distance caused by gravity. The defect of this method is that it is impossible to completely eliminate the braking descent distance caused by braking. The redundant design is to set up another backup power supply. When the main power supply is detected to be accidentally powered off, the backup power supply is immediately enabled to power the controller and the motor. This method still has problems in terms of reliability and cost. It only relatively reduces the probability of adverse phenomena, but does not fundamentally solve the problem. Summary of the invention

[0004] The embodiments of the present application provide a collaborative robot power-off protection method, device and storage medium to solve the problem of collaborative robot power-off displacement in related technologies.

[0005] On the one hand, an embodiment of the present application provides a collaborative robot power failure protection system, the system comprising a power supply, a robot control cabinet, a power failure detection module and a discharge module, the power supply provides a normal working voltage to the control cabinet, and the collaborative robot body receives the control instructions output by the control cabinet and performs corresponding control operations;

[0006] The power-off detection module is connected to the control cabinet and collects the output voltage of the control cabinet in real time; the discharge output of the discharge module is connected to the control cabinet;

[0007] When the output voltage collected by the power-off detection module is less than the voltage threshold, a discharge trigger signal is sent to the discharge module. The discharge module continues to power the control cabinet based on the trigger signal. The control cabinet sends a motion compensation instruction to the collaborative robot based on the trigger signal to control the target joint of the collaborative robot to lift in the opposite direction of gravity.

[0008] Specifically, the normal operating voltage Vn provided by the power supply to the control cabinet is greater than the voltage threshold Vth. When the power-off detection module detects that the output voltage V of the control cabinet is less than the voltage threshold Vth, it indicates that a power-off / power-off abnormality occurs, triggering the power supply compensation mechanism.

[0009] Specifically, the discharge module is a capacitor or inductor energy storage circuit, and when the normal working voltage Vn is greater than the voltage threshold Vth, the discharge module is charged by the power supply.

[0010] Specifically, the minimum driving voltage of the collaborative robot is Vmin. When the output voltage V of the control cabinet is between the voltage threshold Vth and the minimum driving voltage Vmin, the control cabinet performs voltage compensation and control on the collaborative robot according to the capacity of the discharge module. During the discharge compensation time T between the voltage threshold Vth and the minimum driving voltage Vmin, the target joint of the collaborative robot is controlled to lift in the opposite direction of gravity.

[0011] Specifically, the collaborative robot is a rotary joint serial robot, and the displacement generated by each joint when the power is off and the brake is on is L i During the discharge compensation time T, each joint of the collaborative robot is controlled to pre-lift in the opposite direction of gravity. The pre-lift height of each joint is proportional to the brake drop displacement L. i same.

[0012] Specifically, determine the relationship between the driving angle of each joint motor of the collaborative robot and the joint displacement, and calculate the lifting displacement height L of each joint i The joint drive angle θi under power failure is sent through the control cabinet to the corresponding joint motor of the collaborative robot to move in the anti-gravity direction.

[0013] Specifically, the discharge compensation time T includes acceleration time T1, uniform acceleration time T2, deceleration time T3, uniform speed time T4, acceleration / deceleration time T5, uniform deceleration time T6 and deceleration / deceleration time T7 in sequence;

[0014] In T1, the acceleration a gradually increases, a=J*T1;

[0015] In T2, the acceleration a reaches its maximum, a=amax;

[0016] In T3, the acceleration a gradually decreases, a=amax-J*T3;

[0017] In T4, the acceleration a is 0;

[0018] In T5, the acceleration |a| gradually increases, a=-J*T5;

[0019] In T6, the acceleration |a| reaches the maximum, a = -amax;

[0020] In T7, the acceleration |a| gradually decreases, a=-amax-J*T7;

[0021]

[0022] Where |a| represents the absolute value of acceleration; J is the jerk, J i represents the acceleration of the i-th joint motor, V max Indicates L i The maximum velocity achieved within the displacement.

[0023] Specifically, when the voltage provided by the discharge module is lower than the minimum driving voltage Vmin, the brake of the collaborative robot is locked.

[0024] On the other hand, the present application provides a computer device, comprising a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by the processor to implement the robot power-off protection system described in the above aspect.

[0025] On the other hand, the present application provides a computer-readable storage medium, wherein the readable storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by a processor to implement the robot power-off protection system described in the above aspect.

[0026] The beneficial effects brought about by the technical solution provided in the embodiments of the present application include at least: when an unexpected power outage is detected, the robot can be lifted in the opposite direction during the power outage process according to the direction of the gravity it is currently subjected to, and the lifting distance will offset the distance the robot falls due to gravity when the joint motor brake is closed, thereby achieving protection for users and the working environment in the event of an unexpected power outage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a robot power failure protection system provided in an embodiment of the present application;

[0028] Figure 2 It is a structural schematic diagram of a collaborative robot provided in an embodiment of the present application;

[0029] Figure 3 It is the output voltage curve of the control cabinet detected under abnormal power-off state;

[0030] Figure 4 is a speed change curve diagram within the discharge compensation time provided in an embodiment of the present application;

[0031] Figure 5 It is a schematic diagram of the simulation based on the discharge compensation time and acceleration value. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings. The "multiple" mentioned in this article refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship.

[0033] Figure 1 It is a structural schematic diagram of the robot power-off protection system provided in the embodiment of the present application. The system includes a power supply, a robot control cabinet, a power-off detection module and a discharge module. The power supply is a system power supply, which is responsible for providing a normal working voltage Vn to the control cabinet. The power supply control cabinet is responsible for supplying power to the collaborative robot body and sending relevant control instructions. The collaborative robot is based on the control instructions and performs corresponding control operations. The power-off detection module and the discharge module are auxiliary compensation devices. The power-off detection module is connected to the output end of the control cabinet to collect the power supply voltage output to the collaborative robot in real time, that is, the output voltage V. The discharge output of the discharge module is connected to the control cabinet, specifically to the power input end of the control cabinet, and auxiliary compensation is performed when the power supply fails abnormally.

[0034] The principle of this solution is: when the output voltage collected by the power-off detection is less than the voltage threshold, a discharge trigger signal is sent to the discharge module, and the discharge module continues to supply power to the control cabinet based on the trigger signal. At the same time, the power-off detection module sends a corresponding power supply compensation instruction to the control cabinet to trigger the power supply compensation mechanism. The control cabinet sends a motion compensation instruction to the collaborative robot based on the trigger signal to control the target joint of the collaborative robot to lift in the opposite direction of gravity. In some other embodiments, an additional master control MCU may be provided to receive the trigger signal of the power-off detection module through the MCU and send instructions to the control cabinet, or directly send a power supply compensation instruction to the collaborative robot to start displacement compensation after power failure.

[0035] Figure 2 is a schematic diagram of the structure of a collaborative robot provided in an embodiment of the present application. The collaborative robot is a rotary joint serial robot. Figure 2The figure shows a four-degree-of-freedom rotary joint serial robot. Each degree-of-freedom joint of the collaborative robot is equipped with a corresponding joint motor (drive motor), and the joint is lifted and lowered by the forward or reverse rotation of the motor. When the robot loses power and closes, the joints corresponding to the second and third (marked from bottom to top) links of the robot will fall. The specific drop distance of each joint needs to be obtained through actual testing.

[0036] The motor brake of a collaborative robot is a motor brake. Its function is to prevent the motor from being moved by external forces when the motor is stationary and power is off. Generally, only emergency stop, power off, and servo alarm will send a brake signal. The difference between a brake and an open brake is that when there is no power, the motor shaft of the brake is locked and generally cannot be rotated by external force. The motor with the brake open can rotate freely under external force. The present application refers to the joint / connecting rod drop displacement generated at the moment the brake is locked. Different brake locking mechanisms produce different drop displacements in different parts of the robot, and the present application does not limit this.

[0037] The discharge module introduced in this application is a general energy storage circuit, such as a capacitor or inductor energy storage circuit. Different from other backup power supplies, the energy storage circuit has a specific discharge time. The discharge time can be the falling trend of the voltage curve after the robot is powered off, and the displacement compensation is set within the time period of the discharge compensation delay curve falling.

[0038] Figure 3 It is a curve diagram of the control cabinet output voltage detected under abnormal power-off state. The normal operating voltage provided by the power supply to the control cabinet is Vn. The voltage threshold for power-off detection judgment set for the power-off detection module is Vth, and Vn>Vth. When the Vn output by the power supply is greater than the voltage threshold Vth, the discharge module is charged by the power supply; when the normal operating voltage Vn is less than the voltage threshold Vth, the discharge module discharges. For the power-off detection module, when it is detected that the output voltage V of the control cabinet is less than the voltage threshold Vth, it indicates that a power-off / power-off abnormality has occurred, and the power supply compensation mechanism is triggered, that is, a discharge trigger signal is sent to the discharge module. When the discharge module is activated and turned on, the discharge module is charged by the power supply. Figure 2 The dotted line in (power-off curve without discharge compensation) is switched to Figure 2 In the solid line part (the offline curve after discharge compensation is turned on), under general conditions, the larger the capacity of the energy storage circuit, the stronger the delay effect on the curve and the longer the compensation time.

[0039] Set the minimum driving voltage of the collaborative robot to Vmin, that is, the robot can only be controlled when the output voltage V of the control cabinet is greater than the minimum driving voltage Vmin. Vmin is also the threshold voltage that triggers the brake lock. The time period when the output voltage V of the control cabinet is between the voltage threshold Vth and the minimum driving voltage Vmin is the time left for the system to perform voltage compensation and control adjustment on the robot. This time is recorded as the discharge compensation time T. During the discharge compensation time T between the voltage threshold Vth and the minimum driving voltage Vmin, the target joint of the collaborative robot can be controlled to lift in the opposite direction of gravity. Figure 2 and Figure 3 The embodiment of the collaborative robot with power-off protection function has longer second and third links. Therefore, it is only necessary to control the joints corresponding to the second and third links of the robot to move in the opposite direction before the voltage of the control cabinet drops below Vmin, so that the robot can be lifted in the opposite direction of gravity for a certain distance, thereby achieving the power-off protection effect. The specific displacement is determined by the posture of the robot arm, so the displacement of each joint of the device when the power-off brake is set to L i , within the discharge compensation time T, control the pre-lift height L of each joint i The height of the robot, that is, the height of the advance lift, is the height of the normal drop when the power is off, so as to achieve complementary descent and lift. During the testing phase, a large number of experiments are required to collect the falling distance and corresponding falling angle of each joint motor of the collaborative robot in different postures, so as to estimate a unified driving angle required for the joint motor to lift when the robot is powered off and lifted. Since the robot is in different postures, the direction of the current gravity direction of each joint of the robot has different directions of rotation effects on its joints, so it is also necessary to determine the positive and negative driving angles of each joint motor when the power is off and lifted. The current gravity direction of each joint of the robot can be calculated by the robot dynamics, and then the positive and negative driving angles of each joint motor when the power is off and lifted are determined. When a power outage occurs, the joint drive angle θi of the anti-gravity direction is sent to the corresponding joint motor of the collaborative robot through the control cabinet, where i represents the i-th joint / joint motor.

[0040] In some embodiments, the brake locking time is extremely fast. When the joint falls and displaces a large amount, it is necessary to ensure that the joint is lifted to a certain height in time within the discharge compensation time T. This process requires the motors of each joint to run immediately. The motor movement may be too stiff, resulting in a large impact, which may bring certain safety risks in some usage scenarios. For this reason, the present application provides a set of gentle posture control mechanisms. Within the discharge compensation time T, the control cabinet pre-lifts each joint in the opposite direction of gravity according to a specific trajectory planning algorithm.

[0041] The trajectory planning algorithm designed in this application divides the discharge compensation time T into seven consecutive time periods, namely T1-T7. The seven time periods are marked as: acceleration time T1, uniform acceleration time T2, deceleration time T3, uniform speed time T4, acceleration and deceleration time T5, uniform deceleration time T6 and deceleration time T7.

[0042] Figure 4 is a speed change curve diagram within the discharge compensation time provided in an embodiment of the present application;

[0043] In T1, the acceleration a gradually increases, a=J*T1;

[0044] In T2, the acceleration a reaches its maximum, a=amax;

[0045] In T3, the acceleration a gradually decreases, a=amax-J*T3;

[0046] In T4, the acceleration a is 0;

[0047] In T5, the acceleration |a| gradually increases, a=-J*T5;

[0048] In T6, the acceleration |a| reaches the maximum, a = -amax;

[0049] In T7, the acceleration |a| gradually decreases, a=-amax-J*T7;

[0050] In the above formula, |a| represents the absolute value of acceleration, J is the jerk, which represents the flexibility of motor operation. The greater the flexibility, the greater the overshoot and the shorter the running time; the smaller the flexibility, the smaller the overshoot and the longer the running time; V max Indicates L i The maximum speed achieved within the displacement. Different joints have their own velocity change curves and jerks, so the jerk can also be expressed as follows:

[0051]

[0052] J i represents the acceleration of the motor of the i-th joint, in particular, V of different joints max with a max They are also not exactly the same.

[0053] Figure 5This is a simulation diagram based on the discharge compensation time and acceleration value. The upper part is the time-motion position curve of the motor, the middle part is the time-velocity curve of the motor, and the lower part is the time-acceleration curve of the motor. The velocity curve is the first-order derivative of the position curve, and the acceleration curve is the second-order derivative of the position curve. Because the acceleration curve presents different states such as acceleration, uniform speed, and deceleration, the displacement presents a more gentle motion curve. The impact force in actual control is very small, and the movement is softer, further optimizing the user experience and safety. In terms of the time-motion position curve, the curve presents a slow S-shaped trend. Under the regulation of multi-level acceleration changes, the movement is more gentle and the impact force is lower, which minimizes the safety risks to people.

[0054] To summarize, when the collaborative robot with power-off protection function detects an unexpected power outage in the system provided by the present application, the robot can lift the robot in the opposite direction during the power outage according to the direction of the gravity it is currently subjected to, thereby providing temporary power to the control cabinet during the power outage, slowing down the voltage drop curve of the control cabinet, and extending the time it takes for the control cabinet to drop from normal voltage to the minimum control voltage.

[0055] On the other hand, the present application provides a computer device, comprising a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by the processor to implement the robot power-off protection system described in the above aspect.

[0056] On the other hand, the present application provides a computer-readable storage medium, wherein the readable storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by a processor to implement the robot power-off protection system described in the above aspect.

[0057] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A robot power failure protection system, characterized in that: The system includes a power supply, a robot control cabinet, a power failure detection module and a discharge module. The power supply provides a normal working voltage to the control cabinet, and the collaborative robot body receives the control instructions output by the control cabinet and performs corresponding control operations. The power-off detection module is connected to the control cabinet and collects the output voltage of the control cabinet in real time; the discharge output of the discharge module is connected to the control cabinet; When the output voltage collected by the power-off detection module is less than the voltage threshold, a discharge trigger signal is sent to the discharge module. The discharge module continues to power the control cabinet based on the trigger signal. The control cabinet sends a motion compensation instruction to the collaborative robot based on the trigger signal to control the target joint of the collaborative robot to lift in the opposite direction of gravity.

2. The robot power failure protection system according to claim 1, characterized in that: The normal operating voltage Vn provided by the power supply to the control cabinet is greater than the voltage threshold Vth. When the power-off detection module detects that the output voltage V of the control cabinet is less than the voltage threshold Vth, it indicates that a power-off / power-off abnormality occurs, triggering the power supply compensation mechanism.

3. The robot power failure protection system according to claim 2, characterized in that: The discharge module is a capacitor or inductor energy storage circuit. When the normal operating voltage Vn is greater than the voltage threshold Vth, the discharge module is charged by the power supply.

4. The robot power failure protection system according to any one of claims 1 or 2, characterized in that: The minimum driving voltage of the collaborative robot is Vmin. When the output voltage V of the control cabinet is between the voltage threshold Vth and the minimum driving voltage Vmin, the control cabinet performs voltage compensation and control on the collaborative robot according to the capacity of the discharge module. During the discharge compensation time T between the voltage threshold Vth and the minimum driving voltage Vmin, the target joint of the collaborative robot is controlled to lift in the opposite direction of gravity.

5. The robot power failure protection system according to claim 4, characterized in that: The collaborative robot is a rotary joint serial robot. The displacement of each joint when the power is off and the brake is braked is L. i During the discharge compensation time T, each joint of the collaborative robot is controlled to pre-lift in the opposite direction of gravity. The pre-lift height of each joint is proportional to the brake drop displacement L. i same.

6. The robot power failure protection system according to claim 5, characterized in that: Determine the relationship between the driving angle of each joint motor of the collaborative robot and the joint displacement, and calculate the lifting displacement height L of each joint i The joint drive angle θi under power failure is sent through the control cabinet to the corresponding joint motor of the collaborative robot to move in the anti-gravity direction.

7. The robot power failure protection system according to claim 5, characterized in that: The discharge compensation time T includes acceleration time T1, uniform acceleration time T2, deceleration time T3, uniform speed time T4, acceleration / deceleration time T5, uniform deceleration time T6 and deceleration / deceleration time T7 in sequence; In T1, the acceleration a gradually increases, a=J*T1; In T2, the acceleration a reaches its maximum, a=amax; In T3, the acceleration a gradually decreases, a=amax-J*T3; In T4, the acceleration a is 0; In T5, the acceleration |a| gradually increases, a=-J*T5; In T6, the acceleration |a| reaches the maximum, a = -amax; In T7, the acceleration |a| gradually decreases, a=-amax-J*T7; Where |a| represents the absolute value of acceleration; J is the jerk, J i represents the acceleration of the i-th joint motor, V max Indicates L i The maximum velocity achieved within the displacement.

8. The robot power failure protection system according to claim 4, characterized in that: When the voltage provided by the discharge module is lower than the minimum driving voltage Vmin, the brake of the collaborative robot is locked.

9. A computer device, characterized in that: The computer device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the robot power-off protection system as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The readable storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by the processor to implement the robot power-off protection system as described in any one of claims 1 to 7.

Images