Cooperative control method for distributed driving unmanned aerial vehicle

Abstract

The invention discloses a cooperative control method for a distributed driving unmanned aerial vehicle, and relates to a motor control method for an unmanned aerial vehicle. The method comprises the following steps: S1, calculating a feedback gain compensation coefficient of a controlled motor; s2, calculating a synchronous compensation error of each motor; s3, calculating the driving torque of the current virtual main shaft; s4, calculating the output torque of the virtual main shaft; s5, calculating the angular velocity of the virtual spindle at the current moment according to the output torque and the rotational inertia of the virtual spindle; s6, the driving torque of each motor is calculated according to the angular velocity of the current virtual spindle, the angular velocity of each motor at the previous moment and the synchronous compensation error, and the driving torque is fed back to a forward channel of the virtual spindle controller; and S7, updating the current angular velocity of each motor according to the synchronous compensation error of each motor on the unmanned aerial vehicle and the angular velocity fed back at the previous moment. And S8, according to the basic formula of the motor, detecting the difference value between the rotating speed of each motor and the reference rotating speed, and measuring the effect of cooperative control of the system.

Description

Technical Field

[0001] The present invention discloses a coordinated control method for a distributed drive unmanned aerial vehicle (UAV) and relates to a motor control method for the UAV. Background Art

[0002] In order to ensure the safe and reliable supply of electricity, drone inspection technology has been widely used in power grid inspections; considering the problem of insufficient driving power of traditional drones, distributed drive systems have gradually become the preferred power solution for drones. However, due to the mutual influence between the distributed drive systems and the complexity of coordinated motion, the control method has high requirements for accuracy and efficiency. For this reason, scholars at home and abroad have proposed a variety of control schemes, such as master control and master-slave control. Among them, master control and master-slave control are primary open-loop control methods with simple control systems. They are widely used in some occasions with low accuracy requirements, but the disadvantage is that they are not applicable to distributed drive drones, which have high requirements for collaborative control accuracy. Therefore, for the collaborative control problem of distributed drive power inspection drones, a more suitable control method is needed to solve the above problems. Summary of the invention

[0003] The purpose of the present invention is to provide a method for cooperative control of distributed drive UAVs, so as to solve the problems of low precision and poor coordination of traditional master-slave control, reduce control time delay, and enhance the robustness of distributed drive systems.

[0004] To achieve the above object, the present invention provides a coordinated control method of a distributed drive UAV, comprising the following steps:

[0005] S1. Calculate the feedback gain compensation coefficient of the controlled motor;

[0006] S2. Collect the current angular velocity of each motor on the drone and calculate the synchronization compensation error of each motor;

[0007] S3. Calculate the driving torque of the current virtual spindle according to the virtual spindle reference angular velocity and the actual angular velocity;

[0008] S4. Calculate the output torque of the virtual spindle according to the driving torque of the virtual spindle on the drone and the driving torque fed back by each motor at the last moment;

[0009] S5. Calculate the angular velocity of the virtual spindle at the current moment according to the output torque and moment of inertia of the virtual spindle;

[0010] S6. Calculate the driving torque of each motor according to the angular velocity of the current virtual spindle and the angular velocity of each motor at the previous moment and the synchronous compensation error, and feed it back to the forward channel of the virtual spindle controller;

[0011] S7. Update the current angular velocity of each motor on the drone according to the synchronous compensation error of each motor and the angular velocity fed back at the previous moment;

[0012] S8. According to the basic formula of the motor, check the difference between the speed of each motor and the reference speed to measure the effect of the system coordinated control.

[0013] Furthermore, in S1, the specific method for calculating the feedback gain compensation coefficient of the controlled motor is:

[0014] The feedback gain compensation coefficient K of each controlled motor i and the remaining motors j is calculated by the following formula: ij :

[0015]

[0016] In the formula, J i is the moment of inertia of motor i.

[0017] Further, in S2, the specific method of calculating the synchronous compensation error of each motor is:

[0018] The synchronous compensation error of each motor is calculated by the following formula:

[0019]

[0020] In the formula, E i represents the synchronous compensation error of the i-th motor, ω i represents the angular velocity of the i-th motor.

[0021] Further, in S3, the specific method of calculating the driving torque of the current virtual spindle according to the virtual spindle reference angular velocity and the actual angular velocity is:

[0022] The driving torque T of the virtual spindle is calculated by the following formula:

[0023]

[0024] In the formula, ω r represents the reference angular velocity of the virtual spindle, ω m represents the angular velocity of the virtual spindle, K m Indicates the elastic modulus of the virtual principal axis.

[0025] Furthermore, if the spindle attenuation coefficient is taken into account, the specific method for calculating the driving torque of the current virtual spindle is:

[0026] The driving torque T of the virtual spindle considering the spindle reduction coefficient is calculated by the following formula:

[0027]

[0028] Where b m Indicates the attenuation coefficient of the virtual spindle.

[0029] Further, in S4, the specific method for calculating the output torque of the virtual main shaft according to the driving torque of the virtual main shaft on the drone and the driving torque fed back by each motor at the last moment is:

[0030] The output torque of the virtual spindle is calculated by the following formula:

[0031]

[0032] Where, T i Indicates the driving torque of each motor fed back to the virtual spindle controller in the forward channel.

[0033] Further, in S5, the specific method of calculating the angular velocity of the virtual spindle at the current moment according to the output torque and moment of inertia of the virtual spindle is:

[0034]

[0035] In the formula, J m Represents the moment of inertia of the main shaft.

[0036] Further, in S6, the specific method of calculating the driving torque of each motor according to the angular velocity of the current virtual spindle and the angular velocity of each motor at the previous moment and the synchronization compensation error is:

[0037] The driving torque of each motor is calculated by the following formula:

[0038]

[0039] Where b s represents the attenuation coefficient of the motor shaft, ω i represents the angular velocity of the i-th motor at the last moment, K s Indicates the spring constant of the motor shaft.

[0040] Further, in S7, the specific method of updating the current angular velocity of each motor on the drone according to the synchronous compensation error of each motor and the angular velocity fed back at the previous moment is:

[0041] The current angular velocity of each motor is calculated by the following formula:

[0042]

[0043] Where, J represents the moment of inertia of the motor, and B represents the damping coefficient of the motor.

[0044] Furthermore, in S8, the specific method of checking the difference between the speed of each motor and the reference speed according to the basic formula of the motor to measure the effect of the coordinated control of the system is:

[0045]

[0046] Where Nr represents the reference speed of the motor, ω i Indicates the angular velocity of each motor.

[0047] The UAV is a multi-rotor UAV, which is a commercially available product; further, it is a quad-rotor UAV.

[0048] The present invention provides a collaborative control method for a distributed drive UAV, which solves the problem of low precision and poor coordination of traditional master-slave control by adopting a virtual spindle-deviation coupling control method, and enhances the robustness of the distributed drive system. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The present invention will be further described below in conjunction with the accompanying drawings.

[0050] Figure 1 The present invention is a workflow diagram of a collaborative control method for a distributed drive UAV.

[0051] Figure 2 This is a virtual spindle control structure diagram of a coordinated control method for a distributed drive UAV according to the present invention.

[0052] Figure 3 This is a deviation coupling control structure diagram of a coordinated control method for a distributed drive UAV of the present invention.

[0053] Figure 4 This is a multi-motor virtual spindle-deviation coupling control simulation model diagram of a coordinated control method for a distributed drive UAV of the present invention.

[0054] Figure 5 This is a multi-motor virtual spindle-deviation coupling control speed diagram of a distributed drive UAV of the present invention.

[0055] Figure 6 This is a speed error diagram of a multi-motor virtual spindle-deviation coupling control of a distributed drive UAV of the present invention. DETAILED DESCRIPTION

[0056] Combination Figure 1-6 As shown, the present invention provides a coordinated control method of a distributed drive UAV, comprising the following steps:

[0057] S1. Calculate the feedback gain compensation coefficient of the controlled motor:

[0058] The feedback gain compensation coefficient K of each controlled motor i and the remaining motors j is calculated by the following formula: ij :

[0059]

[0060] In the formula, J i is the moment of inertia of motor i.

[0061] S2. Collect the current angular velocity of each motor on the drone and calculate the synchronous compensation error of each motor:

[0062] The synchronous compensation error of each motor is calculated by the following formula:

[0063]

[0064] In the formula, E i represents the synchronous compensation error of the i-th motor, ω i represents the angular velocity of the i-th motor.

[0065] S3. Calculate the driving torque of the current virtual spindle according to the virtual spindle reference angular velocity and actual angular velocity:

[0066] The driving torque T of the virtual spindle is calculated by the following formula:

[0067]

[0068] In the formula, ω r represents the reference angular velocity of the virtual spindle, ω m represents the angular velocity of the virtual spindle, K m Indicates the elastic modulus of the virtual principal axis.

[0069] If the spindle reduction coefficient is taken into account, the driving torque T of the virtual spindle taking into account the spindle reduction coefficient can be calculated by the following formula:

[0070]

[0071] Where b m Indicates the attenuation coefficient of the virtual spindle.

[0072] S4. Calculate the output torque of the virtual spindle based on the driving torque of the virtual spindle on the drone and the driving torque fed back by each motor at the last moment:

[0073] The output torque of the virtual spindle is calculated by the following formula:

[0074]

[0075] Where, T i Indicates the driving torque of each motor fed back to the virtual spindle controller in the forward channel.

[0076] S5. Calculate the angular velocity of the virtual spindle at the current moment based on the output torque and moment of inertia of the virtual spindle:

[0077]

[0078] In the formula, J m Represents the moment of inertia of the main shaft.

[0079] S6. Calculate the driving torque of each motor according to the angular velocity of the current virtual spindle and the angular velocity of each motor at the previous moment and the synchronous compensation error, and feed it back to the forward channel of the virtual spindle controller:

[0080] The driving torque of each motor is calculated by the following formula:

[0081]

[0082] Where b s represents the attenuation coefficient of the motor shaft, ω i represents the angular velocity of the i-th motor at the last moment, k s Indicates the spring constant of the motor shaft.

[0083] S7. Update the current angular velocity of each motor according to the synchronous compensation error of each motor on the drone and the angular velocity fed back at the previous moment:

[0084] The current angular velocity of each motor is calculated by the following formula:

[0085]

[0086] Where, J represents the moment of inertia of the motor, and B represents the damping coefficient of the motor.

[0087] S8. According to the basic formula of the motor, check the difference between the speed of each motor and the reference speed to measure the effect of the system coordinated control:

[0088]

[0089] Where Nr represents the reference speed of the motor, ω i Indicates the angular velocity of each motor.

[0090] The UAV is a multi-rotor UAV, which is a commercially available product; further, it is a quad-rotor UAV.

[0091] The simulation conditions of the embodiment of the present invention are shown in Table 1. Figure 2-Figure 6As shown. It can be seen that the method provided by the present invention introduces virtual spindle-deviation coupling control. When a load torque of 10 N·m is applied to motor 1 from 4s to 6s, the speed of each motor starts to decrease at 4s and returns to the target reference speed in about 0.1 seconds. When unloading at 6s, the speed will increase and then quickly recover to 1000r / min. For a load that lasts for a certain period of time, the waveform will fluctuate twice, which will affect the synchronization performance during the process of applying the load and unloading.

[0092] Since only the load torque is applied to the first motor, it can be seen from the simulation results that the speeds of the other three motors decrease simultaneously with the speed of the first motor, showing synchronization, realizing the coordinated control of the distributed drive UAV system, effectively reducing the motion instability of the UAV distributed drive system under complex working conditions, ensuring the accuracy requirements in the driving process, and ensuring that the system can operate stably in various complex environments.

[0093] Table 1 Simulation conditions of the embodiment of the present invention

[0094]

[0095] For the coordinated control problem of distributed drive electric inspection UAVs, the present invention can solve the problem of low precision and poor coordination of traditional master-slave control by adopting a virtual spindle-deviation coupling control method, and enhance the robustness of the distributed drive system.

Claims

1. A method for cooperative control of a distributed drive UAV, characterized in that: The steps include: S1. Calculate the feedback gain compensation coefficient of the controlled motor; S2. Collect the current angular velocity of each motor on the drone and calculate the synchronization compensation error of each motor; S3. Calculate the driving torque of the current virtual spindle according to the virtual spindle reference angular velocity and the actual angular velocity; S4. Calculate the output torque of the virtual spindle according to the driving torque of the virtual spindle on the drone and the driving torque fed back by each motor at the last moment; S5. Calculate the angular velocity of the virtual spindle at the current moment according to the output torque and moment of inertia of the virtual spindle; S6. Calculate the driving torque of each motor according to the angular velocity of the current virtual spindle and the angular velocity of each motor at the previous moment and the synchronous compensation error, and feed it back to the forward channel of the virtual spindle controller; S7. Update the current angular velocity of each motor on the drone according to the synchronization compensation error of each motor and the angular velocity fed back at the previous moment. S8. According to the basic formula of the motor, check the difference between the speed of each motor and the reference speed to measure the effect of the system coordinated control.

2. The coordinated control method of a distributed drive UAV according to claim 1, characterized in that: In S1, the specific method for calculating the feedback gain compensation coefficient of the controlled motor is: The feedback gain compensation coefficient K of each controlled motor i and the remaining motors j is calculated by the following formula: ij : In the formula, J i is the moment of inertia of motor i.

3. The coordinated control method of a distributed drive UAV according to claim 1, characterized in that: In S2, the specific method for calculating the synchronous compensation error of each motor is: The synchronous compensation error of each motor is calculated by the following formula: In the formula, E i represents the synchronous compensation error of the i-th motor, ω i represents the angular velocity of the i-th motor.

4. The coordinated control method of a distributed drive UAV according to claim 1, characterized in that: In S3, the specific method for calculating the driving torque of the current virtual spindle according to the virtual spindle reference angular velocity and the actual angular velocity is: The driving torque T of the virtual spindle is calculated by the following formula: In the formula, ω r represents the reference angular velocity of the virtual spindle, ω m represents the angular velocity of the virtual spindle, K m Indicates the elastic modulus of the virtual principal axis.

5. The coordinated control method of a distributed drive UAV according to claim 1, characterized in that: In S3, if the spindle attenuation coefficient is considered, the specific method for calculating the driving torque of the current virtual spindle is: The driving torque T of the virtual spindle considering the spindle reduction coefficient is calculated by the following formula: Where b m Indicates the attenuation coefficient of the virtual spindle.

6. The coordinated control method of a distributed drive UAV according to claim 1, characterized in that: In S4, the specific method for calculating the output torque of the virtual main shaft according to the driving torque of the virtual main shaft on the drone and the driving torque fed back by each motor at the last moment is: The output torque of the virtual spindle is calculated by the following formula: Where, T i Indicates the driving torque of each motor fed back to the virtual spindle controller in the forward channel.

7. The coordinated control method of a distributed drive UAV according to claim 1, characterized in that: In S5, the specific method for calculating the angular velocity of the virtual spindle at the current moment according to the output torque and moment of inertia of the virtual spindle is: In the formula, J m Represents the moment of inertia of the main shaft.

8. The coordinated control method of a distributed drive UAV according to claim 1, characterized in that: In S6, the specific method for calculating the driving torque of each motor according to the angular velocity of the current virtual spindle and the angular velocity of each motor at the previous moment and the synchronous compensation error is: The driving torque of each motor is calculated by the following formula: Where b s represents the attenuation coefficient of the motor shaft, ω i represents the angular velocity of the i-th motor at the last moment, K s Indicates the spring constant of the motor shaft.

9. The coordinated control method of a distributed drive UAV according to claim 1, characterized in that: In S7, the specific method of updating the current angular velocity of each motor on the drone according to the synchronous compensation error of each motor and the angular velocity fed back at the previous moment is: The current angular velocity of each motor is calculated by the following formula: Where, J represents the moment of inertia of the motor, and B represents the damping coefficient of the motor.

10. The coordinated control method of a distributed drive UAV according to claim 1, characterized in that: In S8, the specific method of checking the difference between the speed of each motor and the reference speed according to the basic formula of the motor and measuring the effect of the system coordinated control is: Where Nr represents the reference speed of the motor, ω i Indicates the angular velocity of each motor.

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