Self-propelled working machine and mower

Abstract

The application discloses a self-walking working machine and a mower. The self-walking working machine comprises a first walking assembly, a first driving motor for driving the first walking assembly, a second walking assembly, a second driving motor for driving the second walking assembly, and a control circuit capable of controlling the operation of the first driving motor or the second driving motor. The control circuit is configured to control one of the two driving motors to operate in a first control mode and control the other of the two driving motors to operate in a second control mode. The output parameter of the first control mode is used as the input parameter of the second control mode. The control mode can accurately control the working machine to walk along a preset route in a double-motor driving walking mode, and the control process has high robustness.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a large garden tool, for example, a self-propelled working machine and a mower. BACKGROUND

[0002] The intelligent mowing robot is the main development direction of the garden product. In order to better control the walking wheels on the left and right sides of the mower, a driving motor is usually arranged for each walking wheel. Under the control of the double driving motors, the walking wheels can better follow the preset path, such as walking in a straight line or turning. However, when the two driving motors control the walking of the mower together, due to the clock frequency of the control chip and the software control precision, there is a difference between the speed of the two driving motors and the respective set values, which causes the straight line to be not straight and the arc to be not round, resulting in the problem that the driving path of the whole vehicle deviates from the preset path. SUMMARY

[0003] To solve the problems in the prior art, the present application provides a mower which can accurately control the walking path, avoid deviation, and has high robustness.

[0004] To achieve the above-mentioned target, the present application adopts the following technical solutions:

[0005] A self-propelled working machine comprises a first walking assembly, a first driving motor driving the first walking assembly, a second walking assembly, a second driving motor driving the second walking assembly, and a control circuit capable of controlling the operation of the first driving motor or the second driving motor. The control circuit is configured to control one of the two driving motors in a first control mode and control the other of the two driving motors in a second control mode. The output parameter of the first control mode is used as the input parameter of the second control mode.

[0006] Further, the control circuit is a FOC control circuit.

[0007] Further, the first control mode is a FOC control with a first control loop and a second control loop.

[0008] The second control mode is a FOC control with the first control loop, the second control loop, and a third control loop.

[0009] Further, the set input parameter of the third control loop is the output parameter of the driving motor in the first control mode; the feedback parameter of the third control loop is the output parameter of the driving motor in the second control mode; and the output parameter of the third control loop is the set input parameter of the second control loop of the driving motor in the second control mode.

[0010] Further, the control circuit is configured to: detect a rotation state parameter of the first driving motor and the second driving motor; determine a master driving motor and a slave driving motor according to the rotation state parameter; control the master driving motor to operate in the first control mode, and control the slave driving motor to operate in the second control mode.

[0011] Further, the control circuit is configured to: detect a rotation state parameter of the first driving motor and the second driving motor; determine a master driving motor and a slave driving motor according to the rotation state parameter; control the master driving motor to operate in the first control mode, and control the slave driving motor to operate in the second control mode.

[0012] Further, the control circuit is configured to: detect a rotation state parameter of the first driving motor and the second driving motor; determine a master driving motor and a slave driving motor according to the rotation state parameter; control the master driving motor to operate in the first control mode, and control the slave driving motor to operate in the second control mode.

[0013] Further, the first control loop is a current loop, the second control loop is a speed loop, and the third control loop is a number of turns loop.

[0014] A mower comprises: a first walking assembly and a first driving motor for driving the first walking assembly; a second walking assembly and a second driving motor for driving the second walking assembly; and a control circuit for controlling operation of the first driving motor or the second driving motor, wherein the control circuit is configured to: detect a rotation state parameter of the first driving motor and the second driving motor; determine a master driving motor and a slave driving motor according to the rotation state parameter; control the master driving motor to operate in a first control mode, and control the slave driving motor to operate in a second control mode.

[0015] Further, the control circuit is a FOC control circuit, the first control mode is FOC control with a first control loop and a second control loop, and the second control mode is FOC control with the first control loop, the second control loop and a third control loop.

[0016] The present application has the advantage of providing a control mode for a working machine capable of precisely controlling double-motor driving walking according to a preset route, and the control process has high robustness. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural diagram of a mower provided by an embodiment of the present application;

[0018] Figure 2 is a control logic diagram of a driving walking motor in the prior art;

[0019] Figure 3 is a logic control diagram of a driving walking motor provided by an embodiment of the present application;

[0020] Figure 4A logic control chart for driving a walking motor is provided in the embodiments of the present application.

[0021] Figure 5 A control method flow chart for driving a walking motor is provided in the embodiments of the present application. DETAILED DESCRIPTION

[0022] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures.

[0023] In the present application, the self-walking working machine can be any kind of large garden tool, such as a mower, a snow blower, a small cart, etc. It can also be any tool equipment driven by at least two driving motors to drive the walking wheels respectively.

[0024] In the present embodiment, a mower is taken as an example. Referring to the mower 100 shown in Figure 1 The mower 100 mainly includes a handle device 11, a connecting rod 111, an operating member 112, an operating switch 112a, a main machine 12, and a walking assembly 121. The handle device 11 includes the connecting rod 111 and the operating member 112 for holding. The operating member 112 includes a holding part for a user to hold and the operating switch 112a. The connecting rod 111 is a hollow long rod structure, and the connecting rod 111 connects the operating member 112 and the main machine 12. The walking assembly 121 is installed on the main machine 12, and the walking assembly 121 can rotate around a rotating shaft so that the entire mower 100 can move on the ground. It can be understood that the walking assembly 121 is the walking wheel of the mower 100. The walking assembly 121 includes a first walking assembly 1211 and a second walking assembly 1212. The first walking assembly 1211 is located on one side of the mower 100, and the second walking assembly 1212 is located on the other side of the mower 100. The walking assembly 121 in the present embodiment can include a walking wheel.

[0025] In the present embodiment, the first walking assembly 1211 is driven by a first driving motor 1221, and the second walking assembly 1212 is driven by a second driving motor 1222. That is, the walking wheels on both sides of the mower 100 are driven by two different driving motors respectively. The main machine 12 of the mower 100 is also provided with a control board (not shown), and a control circuit 123 on the control board can control the operation of the first driving motor 1211 or the second driving motor 1212. Alternatively, each driving motor can correspond to a control circuit respectively, and one control circuit controls the operation of one driving motor.

[0026] In the present embodiment, the control circuit 123 is a FOC control circuit. As shown inFigure 2 As shown, the commonly used FOC control circuit 123 is a double closed-loop control system, which has a speed regulating system with current inner loop and speed outer loop. The current inner loop is nested in the speed outer loop, and the output of the speed regulator is the given current, and the current inner loop actually controls the motor torque. Specifically, the motor stator current is decomposed into excitation component current i d * and torque component current i q * . Generally, the excitation current is given value i d * 0, and the speed at which the motor is expected to run is set as the given value of the speed loop n * , and the output value of the speed loop input after the PID regulator is used as the given value of the torque component of the current loop i q * . i d * and i q * the output of the PID regulator is u d , u q . u d and u q After park inverse transformation and SVPWM modulation, the PWM wave is output to the inverter drive end, and the three-phase current controlled by the motor is output by the inverter i a , i b , i c . In this way, the speed and current loop control for the driving motor is realized, so that the motor can obtain stable speed control.

[0027] It can be understood that the working machine has double walking assemblies, and each walking assembly on the side is driven and controlled by a different motor. When straight walking is required, the two motors should rotate the same number of turns, but only relying on the double closed-loop control system of the PI regulator, due to the existence of steady-state error, the actual speed of the two motors may fluctuate within the error range, and finally the walking trajectory may not be a straight line. When mass production, due to the unclear differential relationship between the two motors, different directional turning deviations will occur under the straight line command.

[0028] To solve the above problems, in the embodiments of the present application, the FOC control circuit 123 can control the two driving motors corresponding to the two driving wheels in two different control modes. Specifically, the control circuit 123 can detect the rotation state parameters of the two driving motors respectively, and after comparing the rotation state parameters of the two motors, the driving motors on the two sides are divided into master motors and slave motors. And the master motor and the slave motor are controlled in different ways. The so-called comparison of the rotation state parameters of the two motors can be the comparison of the size, ratio or difference of the rotation state parameters of the two motors. Further, the control circuit 123 controls the operation of the master driving motor in the first control mode and the operation of the slave driving motor in the second control mode. The method of distinguishing the master and slave driving motors will be described in the subsequent real-time mode. In this embodiment, the rotation state parameter of the motor can be any one or more of the rotation number, speed, rotor position of the motor, or the orientation of the turning radius of the mower or the walking state. Among them, the walking state and the orientation of the turning radius of the mower can represent the bending direction of the arc line of the mower under the current instruction, that is, the steering of the mower. The rotation number of the motor can be the total number of motor rotations under a certain walking state. Optionally, the rotation number of the motor can be an integer number or a non-integer number.

[0029] In one embodiment, the first control mode is a FOC control mode with a first control loop and a second control loop, and the second control mode is a FOC control mode with a first control loop, a second control loop and a third control loop. It should be noted that the output parameter of the driving motor in the first control mode can be used as the set input parameter of the third control loop of the driving motor in the second control mode, and the feedback parameter or actual parameter of the third control loop is the output parameter of the driving motor in the second control mode; and the output parameter of the third control loop is the input parameter of the second control loop of the driving motor in the second control mode. That is, the output parameter of one motor in the two control modes is used as the preset output parameter of the other motor, so that the running state of the other motor can be adjusted according to the running state of one motor, so that the two motors have the same motion state.

[0030] In one embodiment, the first control loop in the first control mode is a current loop, and the second control loop is a speed loop. The first control mode is a speed current loop control under the traditional FOC control as shown in the figure. Figure 2 The first control loop and the second control loop in the second control mode are also current loop and speed loop, and the third control loop is a number loop. The so-called number loop, also known as position loop, is the output parameter obtained by PID adjusting the actual rotation number and the set number of the motor as the set input parameter of the speed loop.

[0031] In one embodiment, the control circuit 123 can include a first control unit corresponding to the first driving motor 1211 and a second control unit corresponding to the second driving motor 1212, and a communication unit (not shown) is arranged between the two control units. Thus, the two control units can interact data after detecting the rotation state parameters of the driving motors, so that the two control units can distinguish the master motor and the slave motor in the two driving motors according to the detected parameters. In one embodiment, the motor rotor position and the actual number of rotations of the motor during the rotation of the motor can be detected in real time by an encoder, and the rotor position or the number of rotations of the motor can also be obtained by a non-encoder mode through position estimation. The encoder can be an optical encoder. The way of obtaining the number of rotations or the rotor position of the motor in the embodiment of the application is not limited.

[0032] In an optional implementation, when the motor rotates one electrical period, the electrical angle thereof is 0° to 360°. By detecting the difference between the electrical angle at the current moment and the electrical angle at the last moment, it can be determined whether the motor has passed one electrical period. Since the motor has two rotation modes, forward rotation and reverse rotation, the change trend of the electrical angle has two modes, 0° to 360° or 360° to 0°. Therefore, when judging the angle difference, the absolute value of the angle difference needs to be taken as the judgment condition. When the absolute value of the difference is greater than a certain fixed value, it is considered that the electrical angle of the motor has rotated one circle, so that it is determined that the motor has rotated 1 / P turns, where P represents the pole pair number of the motor. In one embodiment, in order to improve the calculation accuracy of the number of rotations of the motor, the sampling frequency of the electrical angle is greater than the rotation frequency of the electrical angle. Further, in order to improve the accuracy of the number of rotations comparison, the comparison accuracy of the number of rotations of the motor can be improved to 0.5 turns or 0.1 turns, etc.

[0033] In one embodiment, the control circuit 123 can distinguish the master and slave motors according to a rotation state parameter of the driving motor. The rotation state parameter can include rotation speed, rotation circle number, rotor position, rotation direction, etc. That is, the control circuit 123 can determine the master and slave motors according to the information of the walking instruction before the motor rotates, i.e., before the mower walks. For example, when the walking instruction is left turn, the control circuit 123 determines the right motor as the master motor; when the walking instruction is right turn, the control circuit 123 determines the left motor as the master motor; and when the walking instruction is straight, the control circuit 123 optionally determines one motor as the master motor. During the walking of the mower, the control circuit 123 can also determine the master and slave motors according to the rotation circle number or rotation speed of the motor under one instruction. For example, the driving motor with more rotation circle number or faster rotation speed can be determined as the master motor, and the other driving motor can be determined as the slave motor. For example, after the motor rotates, the master and slave relationship of the two motors can be determined according to the absolute value of the given speed amplitude of the motor. The motor with faster rotation speed is determined as the master motor. The main reason is that the distance traveled by the two motors in the same time is equal to the ratio of the rotation circle number of the two motors. Assuming that the distance traveled or the rotation circle number ratio of the two motors is: fast motor / slow motor=N (N>1). If the slow motor is determined as the master motor, when the slow motor has an error in counting the circle number, the fast motor is determined as the slave motor, and the reference circle number will magnify the error of the slow motor by N times, which is not conducive to control. On the contrary, if the fast motor is determined as the master motor, the reference circle number of the slow motor will reduce the error of the fast motor by N times, which is conducive to control. Of course, when the rotation speed or rotation circle number of the two driving motors is the same, either of the two motors can be determined as the master motor, and the other motor can be determined as the slave motor.

[0034] In an optional implementation, the control circuit 123 can detect the walking state of the mower and determine the master and slave motors according to the walking state. For example, when the mower walks in a straight line, the control circuit 123 can determine any driving motor as the master motor and the other motor as the slave motor; when the mower has a walking radius to the left, the control circuit 123 determines the right driving motor as the master motor; and when the mower has a walking radius to the right, the control circuit 123 determines the left driving motor as the master motor.

[0035] In this embodiment, after the master and slave motors are determined, the first control mode can be used to control the operation of the master motor, and the second control mode can be used to control the operation of the slave motor. In a specific implementation, as shown in FIG. 12, it is assumed that the first driving motor 1211 is the master motor, and the second driving motor 1212 is the slave motor. According to the first control mode, the control circuit 123 can determine the given speed of the master motor according to the walking speed of the mower, and determine the given speed of the slave motor according to the given speed of the master motor and the master-slave relationship. For example, the given speed of the master motor is determined as V, and the given speed of the slave motor is determined as V / 2. The control circuit 123 can control the master motor to rotate at the given speed V, and control the slave motor to rotate at the given speed V / 2. In this way, the two driving motors can rotate at the same speed, and the walking speed of the mower is equal to the given speed of the master motor. Figure 3 Figure 3 ​It can be seen that the FOC control of the first driving motor 1211 is consistent with the speed current loop control of the traditional FOC, which will not be described in detail here. The difference is that the output parameter of the first driving motor 1211, i.e., the number of rotations of the motor, is output to the third control loop of the second driving motor 1212 as a set input parameter of the third control loop, i.e., the number of loops. In an implementation, a controller 1231 is provided in the third control loop. The controller 1231 can obtain the number of rotations of the first driving motor 1211 and the number of rotations of the second driving motor 1212, and generate a set input parameter of the second control loop, i.e., the speed loop, i.e., a set speed, by modulating the number of rotations of the first driving motor 1211 as a set input parameter and the number of rotations of the second driving motor 1212 as a feedback parameter. It should be noted that the control process of the current loop and the speed loop in the second driving motor 1212 can refer to the control process of the speed current loop of the traditional FOC to realize the rotation control of the second driving motor 1212, which will not be described in detail here. By taking the number of rotations of the master motor as the input parameter of the rotation adjustment of the slave motor, the adjustment of the synchronous rotation of the double motors is realized, so that the lawn mower has more accurate route control during the double-motor walking control process, and better walking effect is achieved.

[0036] Based on the above real-time mode, the lawn mower 100 can walk according to the predetermined trajectory, but when an external force interferes, the walking direction of the driving motor will also change, i.e., walking in the direction of the external force. For example, during the walking process of the lawn mower, a person or an object suddenly rushes in and collides with the lawn mower without avoiding obstacles, and the walking direction of the lawn mower deviates from the original path.

[0037] To solve the above problems, the present application provides the following embodiments:

[0038] In one embodiment, as shown in Figure 4 In one embodiment, as shown in

[0039] In one embodiment, the correction module 124 comprises an IMU unit. The IMU unit can read the actual angle value of the deflection of the mower, and adjust the number of rotations output by the second drive motor 1212 according to the difference between the actual angle value and the set angle value, thereby achieving the purpose of correcting the difference between the number of rotations of the first drive motor 1211 and the number of rotations of the second drive motor 1212, and further changing the set input parameter of the speed loop. Thus, the problem of the set parameter output by the third control loop to the second control loop being inaccurate due to the inaccurate rotation parameter of the second drive motor 1212 caused by external force is avoided, and the mower can still travel according to the original route.

[0040] In an optional embodiment, the control circuit 23 can also be a BLDC control circuit or a combination of any two control circuits or other control circuits.

[0041] In this embodiment, in addition to the addition of the correction module 124, the other control processes are the same as those in the embodiments shown in the drawings, and will not be described here. Figure 3

[0042] As shown in the drawings, the application also provides a method for walking behind a pushing working machine, which comprises the following steps: Figure 5

[0043] S101, determining a master motor and a slave motor in the two drive motors according to a start instruction.

[0044] When the machine is started to travel, the start instruction can be a straight travel instruction or a left turn instruction or a right turn instruction. When the start travel instruction is a straight travel instruction, any one of the drive motors can be determined as the master motor and the other as the slave motor; when the start travel instruction is a left turn instruction, the right motor is determined as the master motor and the left motor is determined as the slave motor; when the start travel instruction is a right turn instruction, the left motor is determined as the master motor and the right motor is determined as the slave motor. It can be understood that the above-mentioned left turn instruction or right turn instruction means the left turn and right turn of the machine in the forward direction, and the principle of the left turn and right turn of the machine in the backward direction is the same, which will not be described here.

[0045] S102, controlling the two drive motors to start running in a first control mode.

[0046] It should be noted that when the mower is started, no matter what the start travel instruction is, the control circuit controls the two drive motors to run in the first control mode, such as starting with FOC control of the current speed loop.

[0047] S103, detecting the rotation state parameter of the two drive motors.

[0048] ​​For example, the rotation state parameter can include any one or more of the number of rotations, the rotation speed, the rotor position, or the turning radius direction, or the running state.

[0049] S104, determining the master motor and the slave motor again according to the rotation state parameters of the two driving motors within a certain time.

[0050] It can be understood that during the walking of the machine, the walking instruction will change, and thus the master motor and the slave motor will also change. Therefore, during the walking of the machine, the master motor and the slave motor can be determined again for the changed walking instruction.

[0051] Under the same control instruction, the mower is in a walking state, and in this walking state, the rotation state parameters of the two driving motors within a certain time can be counted. For example, under a left turning instruction, the turning radius direction is to the left, and the rotation speed or the number of rotations of the left driving motor is less than that of the right driving motor, so that the driving motor with the less number of rotations or the slower rotation speed or the turning radius direction can be determined as the slave motor, and the other can be determined as the master motor. Under a straight walking instruction, the rotation speeds or the numbers of rotations of the two driving motors are the same, or the mower walks along a straight line, so that one of the driving motors can be determined as the master motor, and the other as the slave motor.

[0052] S105, controlling the slave motor to run in the second control mode and performing number compensation on the slave motor.

[0053] While the slave motor is controlled to run in the second control mode, the master motor is still controlled to run in the first control mode. It can be understood that the slave motor at this time can still be the initially determined slave motor, or can have changed.

[0054] Note that the above is only a preferred embodiment of the present application and the technical principle applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, re-adjustments and substitutions without departing from the scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A self-propelled working machine, comprising: A first walking component, and a first drive motor that drives the first walking component; A second walking component, and a second drive motor that drives the second walking component; The control circuit can control the operation of the first drive motor or the second drive motor; The control circuit is characterized in that it is configured as follows: One of the two drive motors is controlled to operate using a first control method, and the other of the two drive motors is controlled to operate using a second control method. The output parameters of the first control method are used as the input parameters of the second control method; The control circuit is further configured to: Detect the rotational state parameters of the first drive motor and the second drive motor; The main drive motor and the slave drive motor are determined based on the rotational state parameters. The main drive motor is controlled to operate using the first control method, and the slave drive motor is controlled to operate using the second control method.

2. The self-propelled working machine according to claim 1, characterized in that, The control circuit is an FOC control circuit.

3. The self-propelled working machine according to claim 2, characterized in that, The first control method is FOC control with a first control loop and a second control loop; The second control method is FOC control with the first control loop, the second control loop and the third control loop.

4. The self-propelled working machine according to claim 3, characterized in that, The input parameters for the third control loop are the output parameters of the drive motor under the first control mode; The feedback parameters of the third control loop are the output parameters of the drive motor under the second control mode; The output parameters of the third control loop are the set input parameters of the second control loop for driving the motor under the second control mode.

5. The self-propelled working machine according to claim 3, characterized in that, Also includes: The correction module is used to correct the parameters in the third control loop under the second control mode.

6. The self-propelled working machine according to claim 5, characterized in that, The correction module includes an IMU unit; The correction module can correct the feedback parameters fed back to the third control loop based on the parameters detected by the IMU unit and the preset expected parameters.

7. The self-propelled working machine according to claim 3, characterized in that, The first control loop is a current loop; The second control loop is the speed loop; The third control loop is a loop with multiple turns.

8. A lawnmower, comprising: A first walking component, and a first drive motor that drives the first walking component; A second walking component, and a second drive motor that drives the second walking component; The control circuit can control the operation of the first drive motor or the second drive motor; The control circuit is characterized in that it is configured as follows: Detect the rotational state parameters of the first drive motor and the second drive motor; The main drive motor and the slave drive motor are determined based on the rotational state parameters. The main drive motor is controlled to operate using a first control method, and the slave drive motor is controlled to operate using a second control method, wherein the output parameters of the first control method are used as the input parameters of the second control method.

9. The lawnmower according to claim 8, characterized in that, The control circuit is an FOC control circuit; The first control method is FOC control with a first control loop and a second control loop; The second control method is FOC control with the first control loop, the second control loop and the third control loop.

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