Robot control method, robot control cabinet, and computer-readable storage medium

Abstract

The present application discloses a robot control method, a robot control cabinet, and a computer-readable storage medium. The robot control method comprises: receiving a power-on command; after receiving the power-on command, controlling the motors of each joint axis of the robot to power on within a preset duration, wherein the power-on times of the motors of each joint axis are different, each joint axis motor is connected to an inverter circuit, and the preset duration is the same as the switching cycle of the switching tube in the inverter circuit. The robot control method provided by the present application can reduce the high-frequency harmonics of the robot, reduce common-mode interference, and improve the robot's operating performance.

Description

Technical Field

[0001] The present application belongs to the field of robotics technology, and specifically relates to a robot control method, a robot control cabinet, and a computer-readable storage medium. Background Art

[0002] In recent years, with the continuous improvement of the automation and intelligence level of the manufacturing industry, industrial robots have developed rapidly. In the field of processing and manufacturing, the application of industrial robots has become more and more mature, so the performance of robots cannot be ignored.

[0003] Currently, multi-axis robots use long heavy-load cables between the robot body and the control cabinet. In order to achieve better EMC (electromagnetic compatibility) effects, a shielding layer is usually added to the periphery of the heavy-load cable. However, the addition of the shielding layer will increase the common-mode interference of the system, thereby affecting the working performance of the robot. Summary of the Invention

[0004] The present application provides a robot control method, a robot control cabinet, and a computer-readable storage medium, which can reduce high-frequency interference of the entire robot, reduce common-mode interference, and improve the working performance of the robot.

[0005] In order to solve the above technical problems, a technical solution adopted in the present application is: to provide a robot control method, the method comprising: receiving a power-on instruction; after receiving the power-on instruction, controlling the motors of each joint axis of the robot to complete power-on within a preset time, wherein the power-on time of the motors of each joint axis is not exactly the same, and the motor of each joint axis is connected to an inverter circuit, and the preset time is the same as the switching cycle of the switch tube in the inverter circuit.

[0006] In order to solve the above technical problems, another technical solution adopted in this application is: to provide a robot control cabinet, which includes: a receiving module for receiving a power-on instruction; a control module electrically connected to the receiving module, and used to control the motors of each joint axis of the robot to complete power-on within a preset time after receiving the power-on instruction, wherein the power-on time of the motors of each joint axis is not exactly the same, and the motors of each joint axis are connected to an inverter circuit, and the preset time is the same as the switching cycle of the switch tube in the inverter circuit.

[0007] To solve the above technical problems, another technical solution adopted in this application is: to provide a robot control cabinet, the robot control cabinet includes a processor and a memory, the processor is coupled to the memory, the memory stores program data, and the processor implements the steps in any of the above methods by executing the program data in the memory.

[0008] To solve the above technical problems, another technical solution adopted in this application is: providing a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program can be executed by a processor to implement the steps in any of the above methods.

[0009] The beneficial effect is that after receiving the power-on command, the control method of the present application controls the motors of each joint axis of the robot to have different power-on times, which can avoid the filter circuit from generating a large common-mode voltage jump and avoid the common-mode voltage waveform being a square wave, thereby reducing the high-frequency harmonics of the robot, reducing common-mode interference, and improving the robot's working performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0011] Figure 1 This is the system circuit diagram of a single-axis robot;

[0012] Figure 2 It is the system circuit diagram of the multi-axis robot;

[0013] Figure 3 This is a flow chart of an embodiment of the robot control method of the present application;

[0014] Figure 4 It is a waveform diagram of the control signal and the common mode voltage signal of the motor of each joint axis when it is powered on in the prior art;

[0015] Figure 5 This is a waveform diagram of the control signals of the motors of each joint axis when powered on in this application;

[0016] Figure 6 This is a waveform diagram of the common mode voltage signal in this application;

[0017] Figure 7 It is a simulation schematic diagram in the prior art;

[0018] Figure 8 It is a simulation diagram of this application;

[0019] Figure 9 This is a structural diagram of an embodiment of the robot control cabinet of the present application;

[0020] Figure 10 This is a structural diagram of another embodiment of the robot control cabinet of the present application;

[0021] Figure 11 It is a structural diagram of an embodiment of a computer-readable storage medium of the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0023] Before introducing the solution of this application, let me first briefly introduce the background of this application:

[0024] A multi-axis robot has multiple joint axes, and each joint axis is correspondingly provided with a motor for driving the rotation of the joint axis. For example, when the robot is a six-axis robot, the robot has six motors.

[0025] Combine Figure 1 However, when the robot is a single-axis robot, its system circuit is divided into three parts, namely the filter circuit 101, the rectifier circuit 102 and the inverter circuit 103. The filter circuit 101 is electrically connected to the power supply for the robot, and the inverter circuit 103 outputs three-phase AC power to control the operation of the motor 105.

[0026] At the same time, in the inverter circuit 103, the switch tubes Q1, Q2 and Q3 are turned on and off at the same time, and the switch tubes Q4, Q5 and Q6 are turned on and off at the same time. The switch tubes Q1 and Q4 form a bridge arm, the switch tubes Q2 and Q5 form a bridge arm, and the switch tubes Q3 and Q6 form a bridge arm. At the same time, for the convenience of explanation, the switch tubes Q1, Q2 and Q3 are called upper tubes in their respective bridge arms, and the switch tubes Q4, Q5 and Q6 are called lower tubes in their respective bridge arms.

[0027] In each bridge arm, the upper switch and the lower switch are turned on in a complementary manner, that is, at the same time, either the upper switch or the lower switch is turned on. At the same time, in the inverter circuit 103, all the switches are of the same model.

[0028] The control circuit 104 is used to control the on / off of each switch in the inverter circuit 103. Specifically, the control circuit 104 outputs control signals to all switches in the inverter circuit 103 simultaneously, and through the coordination between the switches, the motor 105 is powered on and operates.

[0029] Compared with a single-axis robot, in the system circuit of a multi-axis robot, the number of filter circuits 101 and rectifier circuits 102 remains unchanged, while the number of inverter circuits 103 and control circuits 104 changes. Specifically, the number of inverter circuits 103, the number of control circuits 104 and the number of motors 105 are the same. Each motor 105 is connected to an inverter circuit 103, each inverter circuit 103 is connected to a control circuit 104, and all inverter circuits 103 are connected to the rectifier circuit 102 at the same time.

[0030] Among them combined Figure 2 In a multi-axis robot, each motor 105, its corresponding inverter circuit 103, and its control circuit 104 are integrated into one axis. For example, for a six-axis robot, six axes are obtained after integration, namely AXIS 1 to AXIS 6. At the same time, the Cu, Cv, and Cw of each axis are combined to obtain C1, C2, ..., C6.

[0031] Meanwhile, in the multi-axis robot system circuit, the structures of all inverter circuits 103 are the same.

[0032] See Figure 3 , Figure 3 1 is a flow chart of an embodiment of a robot control method of the present application, the control method comprising:

[0033] S110: Receive a power-on instruction.

[0034] S120: After receiving the power-on command, the motors 105 of each joint axis of the robot are controlled to complete power-on within a preset time. The power-on time of the motors 105 of each joint axis is not exactly the same. The motor 105 of each joint axis is connected to an inverter circuit, and the preset time is the same as the switching cycle of the switch tube in the inverter circuit.

[0035] Among them, the robot control method of the present application is executed by a robot control cabinet that controls the movement of the robot. Before the robot control cabinet controls the movement of the robot, the robot control cabinet must first control the motor 105 of each joint axis to power on (the power-on process is also called the enabling process). At the same time, there is generally an enable button on the robot teach pendant or an enable mark on the interface. After the operator triggers the enable button or enable mark, the robot control cabinet receives the power-on command and then controls the motor 105 of each joint axis to power on.

[0036] The switching cycle of the switch tube refers to the interval between two consecutive switching times of the switch tube in the inverter circuit 103. In each switching cycle, the ratio of the duration of the switch tube being on to the switching cycle is the duty cycle of the switch tube.

[0037] In this embodiment, the motors 105 controlling the joint axes of the robot are powered on at different times, that is, at least two motors 105 are powered on at different times, which can prevent the filter circuit 101 from generating a large common mode voltage instantaneously.

[0038] In related technologies, combined Figure 4 After receiving the power-on command, the robot control cabinet controls the simultaneous power-up of the motors 105 of each joint axis, causing the common-mode voltage signal generated by the filter circuit 101 to become a square wave. This square wave signal contains significant harmonic components, which can increase the robot's electromagnetic interference and hinder its ability to pass relevant electromagnetic interference tests. Furthermore, due to the high amplitude and harmonic content of the square wave signal, the common-mode current is also high, increasing the volume of the common-mode inductor CM in the filter circuit 101. This, in turn, increases the size and cost of the device.

[0039] In this embodiment, by setting the power-on time of the motor 105 controlling each joint axis to be unequal, the common-mode voltage signal generated by the filter circuit 101 can be avoided from being a square wave signal, thereby reducing the harmonic components in the system and reducing the common-mode interference in the robot.

[0040] In this embodiment, step S120 specifically includes: after receiving the power-on instruction, controlling the motors 105 of the respective joint axes to be powered on in sequence within a preset time period.

[0041] Specifically, the motors 105 that control each joint axis are powered on in sequence within a preset time length, that is, the power-on time of each motor 105 is completely different and increases in sequence, which can reduce the increase rate of the common mode voltage in the filter circuit 101, thereby reducing the harmonic component in the common mode voltage signal.

[0042] It should be noted that in other embodiments, the motors 105 of each joint axis may not be powered on sequentially within the preset time length. For example, several motors 105 are powered on at the same time first, and then several other motors 105 are powered on at the same time, as long as at least two motors 105 are powered on at different times.

[0043] Meanwhile, in this embodiment, a sine wave modulation technique is used to sequentially turn on the motors 105 of the joint axes, and adjust the common mode voltage signal of the filter circuit 101 from a square wave in the prior art to a nearly sine wave.

[0044] Specifically, combined Figure 5 When the duty cycle of the switch tube is 50%, the peak-to-peak value of the sine wave is divided into N equal parts (N is the number of joint axes of the robot), and then the motors 105 of the N joint axes are sequentially turned on. For the sake of convenience, N is equal to six for explanation:

[0045] Axis 1: -cos(θ1) = -5 / 6, at this time θ1 = 34°;

[0046] Axis 2: -cos(θ2) = -3 / 6, at this time θ2 = 60°;

[0047] Axis 3: -cos(θ3) = -1 / 6, at this time θ3 = 80°;

[0048] Axis 4: -cos(θ4) = 1 / 6, where θ4 = 100°;

[0049] Axis 5: -cos(θ5)=3 / 6, at this time θ5=120°;

[0050] Axis 6: -cos(θ6)=5 / 6, at this time θ6=146°;

[0051] That is, the θ corresponding to the n-axis n The calculation formula is:

[0052] Formula 1: Where N is the number of joint axes, and n is an integer between 1 and N.

[0053] Then the calculation formula for the turning-on time of the n-axis motor 105 is:

[0054] Formula 2: Among them, T is the switching period of the switch tube.

[0055] That is to say, any two adjacent power-on moments must meet the following conditions:

[0056] Wherein, t1 and t2 are two adjacent power-on moments, and t2 is greater than t1.

[0057] At the same time, in order to further reduce common mode interference, the minimum power-on time t min The following conditions must be met:

[0058] For example, when the robot is a six-axis robot, the minimum power-on time must meet the following requirements:

[0059] It should be noted that, in other embodiments, the minimum power-on time t min It can also be 0.

[0060] After the motors 105 of the robot's joint axes are powered on according to the above power-on timing, the common-mode voltage waveform generated by the filter circuit 101 is as follows: Figure 6As shown by the solid line in the figure, it can be seen that the common-mode voltage waveform at this time is slightly different from its fundamental wave (dashed sine wave). Through Fourier analysis, it can be obtained that the total harmonic distortion of the traditional square wave voltage is about 40%, while the total harmonic distortion of the common-mode voltage waveform of the present application is only 10%. Moreover, the more joint axes there are, the lower the distortion.

[0061] See Figure 7 and Figure 8 From the simulation results, it can be seen from the comparison that when the motors 105 of each joint axis are powered on at the same time, the common-mode voltage waveform generated by the filter circuit 101 is approximately a square wave, and the common-mode current waveform is approximately a triangle wave; and when the sinusoidal wave modulation technology in this embodiment is used to control the motors 105 of each joint axis to be powered on in sequence, the common-mode voltage waveform generated by the filter circuit 101 is approximately a sine wave, and the common-mode current waveform is almost equivalent to a sine wave.

[0062] It should be noted that in the above embodiment, when calculating θ1 to θ6, the inverse function of the cosine function is used. However, in other embodiments, the cosine function, the sine function, or the inverse function of the sine function may be used directly. Accordingly, Formula 1 will also change accordingly, and the conditions satisfied by any two adjacent power-on moments, the conditions satisfied by the minimum power-on moment, etc. will also change accordingly. For example, when the cosine function is used directly, for a six-axis robot:

[0063] Axis 1: cos(θ1)=5 / 6;

[0064] 2nd axis: cos(θ2)=3 / 6;

[0065] 3rd axis: cos(θ3)=1 / 6;

[0066] 4th axis: cos(θ4)=-1 / 6;

[0067] 5th axis: cos(θ5)=-3 / 6;

[0068] 6th axis: cos(θ6)=-5 / 6;

[0069] Then, the power-on time of each motor 105 is determined using Formula 2.

[0070] Accordingly, any two adjacent power-on moments must meet the following conditions:

[0071]

[0072] Minimum power-on time t min The following conditions must be met:

[0073]

[0074] It is understandable that when The sine value of The absolute value of the difference in the sine of or, The cosine value of The absolute value of the difference in the cosine of When the common-mode voltage is 0.01V, the waveform of the final common-mode voltage signal can be guaranteed to be similar to a sine wave.

[0075] It should be noted that when the duty cycle of the switch tube is not 50%, the power-on time of each joint axis motor 105 can also be determined according to the above formula 1 and formula 2. At this time, the waveform of the common mode voltage signal generated by the filter circuit 101 is not as similar to the sine wave as the sine wave. Figure 6 The common mode voltage signal is similar to a sine wave, but compared with the square wave in the existing technology, it can still reduce the high-frequency harmonics of the robot, reduce common mode interference, and improve the working performance of the robot.

[0076] In this embodiment, for ease of management, after receiving a power-on command, the motors 105 controlling each joint axis are powered on sequentially, from closest to the robot base to furthest from the base. That is, if the robot is a six-axis robot, the joint axis closest to the base is defined as axis 1, and the joint axis farthest from the base is defined as axis 6. Of course, in other embodiments, if the robot is a six-axis robot, the joint axis closest to the base can also be defined as axis 6, and the joint axis farthest from the base can be defined as axis 1.

[0077] In the above embodiment, the common-mode voltage signal is made into a near-sine wave signal by controlling the power-on moment of each motor 105. However, in other embodiments, the common-mode voltage signal can also be made into a triangular wave signal or a sawtooth wave signal or other signals by controlling the power-on moment of each motor 105. In short, as long as the common-mode voltage signal is not a square wave signal, it can be used.

[0078] See Figure 9 , Figure 9 2 is a schematic structural diagram of an embodiment of a robot control cabinet of the present application. The robot control cabinet 200 includes a receiving module 210 and a control module 220 .

[0079] The receiving module 210 is used to receive a power-on instruction.

[0080] The control module 220 is connected to the receiving module 210, and is used to control the motors of each joint axis of the robot to complete power-on within a preset time after receiving the power-on command. The power-on time of the motors of each joint axis is not exactly the same. The motor of each joint axis is connected to an inverter circuit, and the preset time is the same as the switching cycle of the switch tube in the inverter circuit.

[0081] The receiving module 210 and the control module 220 cooperate with each other to implement the steps of the robot control method in any of the above embodiments. The detailed steps can be found in the above embodiments and will not be repeated here.

[0082] See Figure 10 , Figure 10 Schematic diagram of the structure of one embodiment of a robot control cabinet of the present application. The robot control cabinet 300 includes a processor 310 and a memory 320. The processor 310 is coupled to the memory 320, which stores program data. The processor 310 executes the program data in the memory 320 to implement the steps of any of the above-mentioned embodiments. The detailed steps can be found in the above-mentioned embodiments and will not be repeated here.

[0083] See Figure 11 , Figure 11 The computer-readable storage medium 400 stores a computer program 410, which can be executed by a processor to implement the steps of any of the above methods.

[0084] Among them, the computer-readable storage medium 400 can specifically be a device that can store the computer program 410, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, or it can also be a server that stores the computer program 410. The server can send the stored computer program 410 to other devices for execution, or it can also run the stored computer program 410 itself.

[0085] The above description is merely an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A robot control method, characterized in that: The method comprises: Receive power-on command; After receiving the power-on instruction, controlling the motors of each joint axis of the robot to complete power-on within a preset time, wherein the power-on time of the motors of each joint axis is not exactly the same, each motor of the joint axis is connected to an inverter circuit, and the preset time is the same as the switching cycle of the switch tube in the inverter circuit; Wherein, after receiving the power-on instruction, the step of controlling the motors of each joint axis of the robot to complete power-on within a preset time includes: After receiving the power-on instruction, controlling the motors of the respective joint axes to be powered on in sequence within the preset time length; Among the power-on moments of the motors of the joint axes, any two adjacent power-on moments satisfy the following conditions: The cosine value of The absolute value of the difference in the cosine of , where T is the switching cycle of the switch tube, N is the number of the joint axes, 、 are two adjacent power-on moments, and Greater than .

2. The method according to claim 1, characterized in that Among the power-on moments of the motors of the joint axes, any two adjacent power-on moments satisfy the following conditions: 。 3. The method according to claim 2, characterized in that Among the power-on times of the motors of the joint axes, the minimum power-on time is The following conditions must be met: 。 4. The method according to claim 1, wherein The step of controlling the motors of the joint axes to be powered on sequentially within the preset time period after receiving the power-on instruction comprises: After receiving the power-on instruction, the motors controlling the joint axes are powered on in sequence from closest to the robot base.

5. A robot control cabinet, characterized in that: The robot control cabinet includes: A receiving module, used for receiving a power-on instruction; a control module, electrically connected to the receiving module, for controlling the motors of the respective joint axes of the robot to power on within a preset time after receiving the power-on instruction, wherein the power-on times of the motors of the respective joint axes are not exactly the same, the motors of each joint axis are connected to an inverter circuit, and the preset time is the same as the switching cycle of the switch tube in the inverter circuit; Wherein, the control module is specifically used for: After receiving the power-on instruction, controlling the motors of the respective joint axes to be powered on in sequence within the preset time length; Among the power-on moments of the motors of the joint axes, any two adjacent power-on moments satisfy the following conditions: The cosine value of The absolute value of the difference in the cosine of , where T is the switching cycle of the switch tube, N is the number of the joint axes, 、 are two adjacent power-on moments, and Greater than .

6. A robot control cabinet, characterized in that: The robot control cabinet includes a processor and a memory, the processor is coupled to the memory, and the memory stores program data. The processor implements the steps in the method according to any one of claims 1 to 4 by executing the program data in the memory.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and the computer program can be executed by a processor to implement the steps in the method according to any one of claims 1 to 4.

Images