WO2021024590A1 - Motor control device, moving body, motor control method, and program - Google Patents

Abstract

This motor control device is provided with an acquiring unit and a motor control unit. The acquiring unit acquires a torque detection value corresponding to the torque generated between a propeller and a motor rotating the propeller. The motor control unit controls the motor on the basis of the torque detection value acquired by the acquiring unit.

Description

Motor control device, moving body, motor control method and program

The present disclosure generally relates to motor control devices, moving bodies, motor control methods and programs. More specifically, the present disclosure relates to a motor control device that controls a motor that rotates a propeller, a moving body including the motor control device, a motor control method, and a program.

Conventionally, a technique for controlling a motor included in a moving body such as a drone is known (see, for example, Patent Document 1). The unmanned aerial vehicle (moving body) described in Patent Document 1 has an attitude control loop. The attitude control loop includes an angular velocity control loop. The angular velocity control loop uses a PI (Proportion Integral) corrector to calculate the angular velocity setting point of the unmanned aerial vehicle. The angular velocity control loop calculates the difference between the angular velocity set point and the angular velocity effectively measured by the gyrometer. Based on this information, various set points are calculated for the rotational speed of the motor (and therefore for lift), and the set points are sent to the motor to perform the motion operation of the drone.

In the unmanned aerial vehicle (moving body) described in Patent Document 1, in order to correct the control of the motor in order to correct the posture of the unmanned aerial vehicle, first, the posture of the unmanned aerial vehicle changes, and then the posture of the unmanned aerial vehicle is changed. Since it is necessary to measure the fluctuation with a gyrometer, there is a problem in the responsiveness of the motor control.

Special Table 2015-514263

It is an object of the present disclosure to provide a motor control device, a moving body, a motor control method and a program capable of improving the responsiveness of motor control.

The motor control device according to one aspect of the present disclosure includes an acquisition unit and a motor control unit. The acquisition unit acquires a torque detection value corresponding to the torque generated between the propeller and the motor that rotates the propeller. The motor control unit controls the motor based on the torque detection value.

The moving body according to one aspect of the present disclosure includes a motor control device, a motor, a propeller, and a moving body main body. A motor, a propeller, and a motor control device are mounted on the main body of the moving body.

The motor control method according to one aspect of the present disclosure includes a first step of acquiring a torque detection value corresponding to a torque generated between a propeller and a motor that rotates the propeller, and a torque detection acquired in the first step. It comprises a second step of controlling the motor based on the value.

The program according to one aspect of the present disclosure is a program for causing one or more processors to execute the motor control method.

The present disclosure has an advantage that the responsiveness of motor control can be improved.

FIG. 1 is a block diagram of a mobile motor control device according to an embodiment. FIG. 2 is a block diagram of the same moving body. FIG. 3 is a perspective view showing a schematic shape of the moving body as described above. FIG. 4 is a flowchart showing an operation example of the moving body as described above. FIG. 5 is a block diagram of the motor control device of the moving body according to the first modification.

Hereinafter, the motor control device 2, the moving body 1, the motor control method, and the program according to the embodiment will be described with reference to the drawings. However, the following embodiments are only one of the various embodiments of the present disclosure. The following embodiments can be variously modified according to the design and the like as long as the object of the present disclosure can be achieved. Further, FIG. 3 described in the following embodiment is a schematic view, and the ratio of the size and the thickness of each component in the figure does not necessarily reflect the actual dimensional ratio. ..

(1) Outline FIG. 1 is a block diagram of a mobile motor control device 2 according to an embodiment. FIG. 2 is a block diagram of the mobile body 1 of the same. As shown in FIG. 2, the moving body 1 includes a plurality of motor control devices 2 (4 in FIG. 2), a plurality of motors 3 (4 in FIG. 2), and a plurality of propellers (4 in FIG. 2). 4 (rotor blade) and a moving body main body 5 are provided. The moving body 1 includes three or more motors 3 and three or more propellers 4. The plurality of motors 3, the plurality of propellers 4, and the plurality of motor control devices 2 are mounted on the moving body main body 5.

The plurality of motors 3 and the plurality of propellers 4 have a one-to-one correspondence. Each propeller 4 is rotated by a force applied from the corresponding motor 3. As a result, torque is generated between each motor 3 and the corresponding propeller 4. When each propeller 4 is rotated by the corresponding motor 3, a thrust for moving the moving body 1 is generated.

The plurality of motor control devices 2 and the plurality of motors 3 have a one-to-one correspondence. Each motor control device 2 controls the corresponding motor 3.

As shown in FIG. 1, each motor control device 2 includes a motor control unit 21, a current sensor 25, and an acquisition unit 26.

In each motor control device 2, the current sensor 25 measures the current flowing through the motor 3. The acquisition unit 26 calculates the torque detection value T1 which is the detection value of the torque current flowing through the motor 3 based on the current measured by the current sensor 25. The torque detection value T1 is a value corresponding to the torque generated between the propeller 4 and the motor 3. The acquisition unit 26 calculates the torque detection value T1 individually in each motor control device 2.

The motor control unit 21 controls the motor 3 based on the torque detection value T1 acquired by the acquisition unit 26.

In the motor control device 2, after the change in torque generated between the propeller 4 and the motor 3, the change occurs even before the posture, speed, etc. of the moving body 1 change as a result of the change in torque. The control of the motor 3 can be changed based on the torque detection value T1. Therefore, the responsiveness of the control of the motor 3 can be improved as compared with the case where the motor 3 is controlled based on the detection result of the posture and speed of the moving body 1. For example, when the posture of the moving body 1 starts to collapse, the posture can be corrected by controlling the motor 3 based on the changed torque detection value T1 before the posture collapse becomes large.

(2) Configuration Hereinafter, the moving body 1 and the motor control device 2 of the present embodiment will be described in more detail. FIG. 3 is a perspective view showing a schematic shape of the moving body 1 according to the embodiment. In the present embodiment, a case where the moving body 1 (see FIG. 3) is a drone (aerial drone) will be described as a typical example. Drones are a type of unmanned aerial vehicle. A drone is a type of multicopter with three or more propellers 4. The drone has the function of flying autonomously. The drone controls the posture of the aircraft (moving body body 5) by controlling the rotation speed of each of the three or more propellers 4. The moving direction of the aircraft changes according to the change in the attitude of the aircraft.

In FIG. 3, the roll axis, pitch axis, and yaw axis of the moving body body 5 are illustrated as X-axis, Y-axis, and Z-axis. As shown in FIG. 3, four propellers 4 are attached to the moving body main body 5. More specifically, the mobile body 5 has four arms 51 extending in four directions. A propeller 4 is attached to the tip of each arm 51 of the moving body body 5. In the following, in order to distinguish the four propellers 4, the four propellers 4 may be referred to as propellers 41, 42, 43, 44, respectively. The four propellers 41 to 44 are arranged in this order (around the yaw axis (Z axis)) in the circumferential direction surrounding the moving body body 5.

Of the four propellers 4, two propellers 41 and 43 rotate in the first direction, and the remaining two propellers 42 and 44 rotate in the second direction opposite to the first direction. The two propellers 4 located diagonally to each other rotate in the same direction.

Each of the four propellers 4 rotates by the driving force of the corresponding motor 3 to generate thrust. In FIG. 3, arrows f1 to f4 indicating the thrust of each propeller 4 and arrows f5 indicating the thrust of the moving body 5 are shown. The direction of thrust of each propeller 4 is the yaw axis direction (upward). In the four propellers 4, the thrusts can be different from each other.

In each of the four propellers 4, the higher the number of revolutions, the greater the thrust. The thrust and posture of the moving body 5 change according to the thrust of each of the four propellers 4. For example, the rotation speeds of the two propellers 41 and 42 provided on the front half of the moving body 1 (on the positive side of the X-axis) are the rotation speeds of the two propellers 43 and 44 provided on the rear half of the moving body 1. By making the size smaller than the above, the moving body 1 tilts forward, so that an upward and forward thrust is generated on the moving body 1 and the moving body 1 moves forward.

The torque acting on the moving body body 5 from the four propellers 4 is also determined by the rotation speed of each of the four propellers 4. For example, suppose that the rotation speeds of the two propellers 41 and 43 located diagonally to each other are made smaller or larger than the rotation speeds of the remaining two propellers 42 and 44. Then, a torque corresponding to the difference between the torques of the two propellers 41 and 43 and the torques of the two propellers 42 and 44 acts on the moving body body 5, so that the moving body body 5 is centered on the yaw axis (Z axis). Rotate.

As shown in FIG. 2, the moving body 1 includes an upper portion 6, a middle portion 7, four motor control devices 2, four motors 3, four propellers 4, a moving body main body 5, and motion. It includes a detection unit 9. Each motor 3 is, for example, a brushless motor. The mobile 1 includes, for example, a computer system having one or more processors and memory. When the processor of the computer system executes the program recorded in the memory of the computer system, at least a part of the functions of the upper unit 6, the intermediate unit 7, and the motor control device 2 are realized. The program may be recorded in a memory, provided through a telecommunication line such as the Internet, or may be recorded and provided on a non-temporary recording medium such as a memory card.

The motion detection unit 9 detects information about the motion of the moving body 1. The detection signal indicating the detection result of the motion detection unit 9 is output to the upper unit 6 and the middle unit 7. The motion detection unit 9 includes, for example, a gyro sensor, an acceleration sensor, a geomagnetic sensor, a GPS (Global Positioning System) sensor, a pressure sensor, and the like. The gyro sensor detects the posture (tilt) of the moving body 1. The acceleration sensor detects the acceleration of the moving body 1. The geomagnetic sensor detects the orientation of the moving body 1. The GPS sensor detects the current position of the moving body 1. The barometric pressure sensor detects the barometric pressure at the current position of the moving body 1.

The motion detection unit 9 calculates the coordinates, velocity, angle, and angular velocity of the moving body 1 based on the outputs of various sensors such as a gyro sensor.

The coordinates of the moving body 1 calculated by the motion detection unit 9 are the X coordinate, the Y coordinate, and the Z coordinate. Here, the directions of the roll axis, pitch axis, and yaw axis when the moving body 1 is not tilted and the rotation axes of the four propellers 4 are parallel to the vertical direction are defined as the X, Y, and Z axis directions. .. The velocities of the moving body 1 calculated by the motion detection unit 9 are the velocities in the X-axis direction and the velocities in the Y-axis direction.

The angle of the moving body 1 calculated by the motion detection unit 9 is the rotation position of the moving body 1 around the roll axis, the pitch axis, and the yaw axis (X, Y, Z axes). The angular velocity of the moving body 1 calculated by the motion detection unit 9 is the angular velocity of rotation around the roll axis, the pitch axis, and the yaw axis.

The upper unit 6 transmits a first instruction signal regarding the control of the four motors 3 to the middle unit 7. The first instruction signal is, for example, at least one of a position instruction signal for instructing the position (altitude and horizontal coordinates) of the mobile body 5 and an attitude instruction signal for instructing the posture (angle) of the mobile body 5. Including one. For example, when the mobile body 1 is stopped on the ground, information on the coordinates of the destination of the mobile body 1 is input to the upper unit 6 by wireless communication or wired communication from an external device of the mobile body 1. .. Further, for example, during the flight of the mobile body 1, the update information of the coordinates of the destination of the mobile body 1 is input to the upper unit 6 by wireless communication from an external device of the mobile body 1. The upper unit 6 generates a position instruction signal and an attitude instruction signal based on the information of the coordinates of the destination of the moving body 1 and the detection signals of the gyro sensor, the GPS sensor, and the like of the motion detection unit 9. As a result, the upper unit 6 controls the four motors 3 so as to direct the moving body 1 to the destination.

The middle unit 7 generates a second instruction signal based on the first instruction signal received from the upper unit 6 and the information about the motion of the moving body 1 received from the motion detection unit 9. The second instruction signal includes, for example, the torque target values Tr1 (or Tr2, Tr3, Tr4) and the thrust target values Fr1 (or Fr2, Fr3, Fr4) of each of the four motors 3. The middle unit 7 generates four second instruction signals and transmits them to the four motor control devices 2. The four second instruction signals can be different from each other. That is, the intermediate portion 7 can give different instructions to the four motors 3 via the four motor control devices 2. Thereby, the posture, the moving direction, the moving speed, the acceleration, and the like of the moving body 1 can be controlled by controlling the rotation speed of each of the four motors 3.

Parameters related to the force applied to the moving body body 5 include acceleration in the yaw axis (Z axis) direction, angular velocity around the roll axis, angular velocity around the pitch axis, and angular velocity around the yaw axis. The acceleration in the yaw axis direction is detected by the acceleration sensor of the motion detection unit 9. The angular velocity around the roll axis, the angular velocity around the pitch axis, and the angular velocity around the yaw axis are detected by the gyro sensor of the motion detection unit 9. The middle unit 7 calculates the target value of each of these four parameters based on the first instruction signal transmitted from the upper unit 6, and feedback-controls the four parameters so that each of the four parameters approaches the target value. ..

The middle portion 7 has an altitude controller 71, a position controller 72, 73, a speed controller 74, 75, an angle controller 76, 77, 78, and an angular velocity controller 79, 80, 81. doing. Each of these performs feedback control. The middle portion 7 further has an indicator portion 82.

A signal including a target value (denoted as Zr in FIG. 2) of the Z coordinate (altitude) of the moving body 1 is input to the altitude controller 71 as the first instruction signal from the upper unit 6. The calculated value of the Z coordinate (denoted as Z in FIG. 2) of the moving body 1 calculated by the motion detection unit 9 is input to the altitude controller 71. The altitude controller 71 determines the total target value Tr of the torques of the four motors 3 so that the difference between the target value of the Z coordinate and the calculated value converges within a predetermined range. The target value Tr is a vector quantity.

A signal including the target value of the X coordinate of the moving body 1 (denoted as Xr in FIG. 2) is input to the position controller 72 as the first instruction signal from the upper unit 6. The calculated value of the X coordinate (denoted as X in FIG. 2) of the moving body 1 calculated by the motion detection unit 9 is input to the position controller 72. The position controller 72 determines the target value Vxr of the velocity in the X-axis direction so that the difference between the target value of the X coordinate and the calculated value converges within a predetermined range.

A signal including a target value of the Y coordinate of the moving body 1 (denoted as Yr in FIG. 2) is input to the position controller 73 as the first instruction signal from the upper unit 6. The calculated value of the Y coordinate (denoted as Y in FIG. 2) of the moving body 1 calculated by the motion detection unit 9 is input to the position controller 73. The position controller 72 determines the target value Vyr of the velocity in the Y-axis direction so that the difference between the target value of the Y coordinate and the calculated value converges within a predetermined range.

In the speed controller 74, the target value Vxr of the velocity in the X-axis direction defined by the position controller 72 and the calculated value Vx of the velocity in the X-axis direction calculated by the motion detection unit 9 are input. The speed controller 74 determines the target value θr of the angle around the Y axis so that the difference between the target value Vxr and the calculated value Vx converges within a predetermined range. By rotating the moving body main body 5 around the Y axis, the speed of the moving body main body 5 in the X-axis direction is adjusted.

The target value Vyr of the velocity in the Y-axis direction defined by the position controller 73 and the calculated value Vy of the velocity in the Y-axis direction calculated by the motion detection unit 9 are input to the speed controller 75. The speed controller 75 determines the target value φr of the angle around the X axis so that the difference between the target value Vyr and the calculated value Vy converges within a predetermined range. By rotating the moving body main body 5 around the X axis, the speed of the moving body main body 5 in the Y axis direction is adjusted.

The angle controller 76 has a target value θr of the angle around the Y axis defined by the speed controller 74 and a calculated value of the angle around the Y axis calculated by the motion detection unit 9 (denoted as θ in FIG. 2). ) And is entered. The angle controller 76 determines the target value ωθr of the angular velocity of rotation around the Y axis so that the difference between the target value θr and the calculated value θ converges within a predetermined range.

The angle controller 77 has a target value φr of the angle around the X axis defined by the speed controller 75 and a calculated value of the angle around the X axis calculated by the motion detection unit 9 (denoted as φ in FIG. 2). ) And is entered. The angle controller 77 determines the target value ωφr of the angular velocity of rotation around the X axis so that the difference between the target value φr and the calculated value φ converges within a predetermined range.

A signal including a target value of an angle around the Z axis (denoted as ψr in FIG. 2) is input to the angle controller 78 as the first instruction signal from the upper unit 6. The calculated value of the angle around the Z axis (denoted as ψ in FIG. 2) calculated by the motion detection unit 9 is input to the angle controller 78. The angle controller 78 determines the target value ωψr of the angular velocity of rotation around the Z axis so that the difference between the target value ψr and the calculated value ψ converges within a predetermined range.

The angular velocity controller 79 has a target value ωθr of the angular velocity of rotation around the Y-axis defined by the angle controller 76 and a calculated value ωθ of the angular velocity of rotation around the Y-axis calculated by the motion detection unit 9. Entered. The angular velocity controller 79 determines the target value τθr of the angular acceleration of rotation around the Y axis so that the difference between the target value ωθr and the calculated value ωθr converges within a predetermined range.

The angular velocity controller 80 has a target value ωφr of the angular velocity of rotation around the X-axis defined by the angle controller 77 and a calculated value ωφ of the angular velocity of rotation around the X-axis calculated by the motion detection unit 9. Entered. The angular velocity controller 80 determines the target value τφr of the angular acceleration of rotation around the X axis so that the difference between the target value ωφr and the calculated value ωφ converges within a predetermined range.

The angular velocity controller 81 has a target value ωψr of the angular velocity of rotation around the Z axis defined by the angle controller 78 and a calculated value ωψr of the angular velocity of rotation around the Z axis calculated by the motion detection unit 9. Entered. The angular velocity controller 81 determines the target value τψr of the angular acceleration of rotation around the Z axis so that the difference between the target value ωψr and the calculated value ωψr converges within a predetermined range.

The indicator 82 rotates around the X, Y, and Z axes defined by the angular velocity controllers 79, 80, and 81, and the target value Tr of the total torque of the four motors 3 defined by the altitude controller 71. Four torque target values Tr1, Tr2, Tr3, Tr4 and four thrust target values Fr1, Fr2, Fr3, and Fr4 are generated based on the target values τφr, τθr, and τψr of the angular acceleration of. The four torque target values Tr1, Tr2, Tr3, Tr4 and the four thrust target values Fr1, Fr2, Fr3, and Fr4 each correspond one-to-one with the four motor control devices 2. The indicator 82 outputs the corresponding torque target value and thrust target value to the four motor control devices 2, respectively. By controlling the motor 3 based on the corresponding torque target value and thrust target value in each of the four motor control devices 2, the measured values are brought closer to the target values Tr, τφr, τθr, and τψr.

In the following, the description will focus on one of the four motor control devices 2. As shown in FIG. 1, each motor control device 2 includes a motor control unit 21, a control output unit 22, a motor rotation measurement unit 23, a power supply circuit 24, a current sensor 25, an acquisition unit 26, and a pressure sensor. 27, a thrust calculation unit 28, and an output unit 29 are provided. The motor control device 2 includes, for example, a computer system having one or more processors and memories. When the processor of the computer system executes the program recorded in the memory of the computer system, at least a part of the functions of the motor control device 2 are realized. The program may be recorded in a memory, provided through a telecommunication line such as the Internet, or may be recorded and provided on a non-temporary recording medium such as a memory card.

The motor control unit 21 includes a torque controller 211, a thrust controller 212, and a current controller 213.

The torque target value Tr1 is input to the torque controller 211 from the indicator unit 82 of the intermediate unit 7. The torque detection value T1 of the motor 3 calculated by the acquisition unit 26 is input to the torque controller 211.

The thrust target value Fr1 is input to the thrust controller 212 from the instruction unit 82 of the middle unit 7. The thrust detection value F1 of the motor 3 calculated by the thrust calculation unit 28 is input to the thrust controller 212.

The motor control unit 21 controls the current flowing through the motor 3 based on the torque detection value T1. More specifically, the motor control unit 21 performs feedback control so that the torque detection value T1 approaches the torque target value Tr1. That is, the motor control unit 21 determines the current target value Ir1 of the current supplied to the motor 3 so that the difference between the torque target value Tr1 and the torque detection value T1 converges within the first predetermined range.

The motor control unit 21 further controls the motor 3 based on the thrust detection value F1 corresponding to the thrust generated by the propeller 4. The thrust detection value F1 is a value calculated by the thrust calculation unit 28. The motor control unit 21 provides feedback control so that the thrust detection value F1 approaches the thrust target value Fr1. That is, the motor control unit 21 determines the current target value Ir1 so that the difference between the thrust target value Fr1 and the thrust detection value F1 converges within the second predetermined range.

In short, in the motor control unit 21, the difference between the torque target value Tr1 and the torque detection value T1 converges within the first predetermined range, and the difference between the thrust target value Fr1 and the thrust detection value F1 is the second predetermined difference. The current target value Ir1 is set so as to converge within the range. The first predetermined range is, for example, a range of -3% to + 3% of the torque target value Tr1. The second predetermined range is, for example, a range of -3% to + 3% of the thrust target value Fr1.

More specifically, the motor control unit 21 has a torque / thrust control unit 210 including a torque controller 211 and a thrust controller 212. The torque controller 211 outputs the difference between the torque target value Tr1 and the torque detection value T1. The thrust controller 212 outputs the difference between the thrust target value Fr1 and the thrust detection value F1. The torque / thrust control unit 210 determines the current target value Ir1 based on the outputs of the torque controller 211 and the thrust controller 212.

Here, the torque and the thrust are weighted by defining the widths (difference between the upper limit value and the lower limit value) of the first predetermined range and the second predetermined range, respectively. The larger the torque weighting, the closer the torque (torque detection value T1) approaches the torque target value Tr1. The greater the weighting of thrust, the closer the thrust (thrust detection value F1) approaches the thrust target value Fr1. The smaller the width of the first predetermined range, the larger the weighting of the thrust, and the more accurately the altitude of the moving body 1 can be controlled. The smaller the width of the second predetermined range, the larger the weighting of the torque, and the more accurately the posture of the moving body 1 can be controlled. Depending on the design, the weighting of torque and thrust is appropriately determined.

The current target value Ir1 defined by the torque / thrust control unit 210 and the measured value I1 of the current flowing through the motor 3 measured by the current sensor 25 are input to the current controller 213. The current controller 213 (motor control unit 21) performs current control for controlling the current flowing through the motor 3 based on the current flowing through the motor 3 (measured value I1). More specifically, the current controller 213 controls the current supplied to the motor 3 so that the difference between the current target value Ir1 and the measured value I1 converges within a predetermined range. That is, the current controller 213 feedback-controls so that the measured value I1 approaches the current target value Ir1.

The power supply circuit 24 is, for example, a switching power supply circuit including a switching element. The power supply circuit 24 passes a current through the motor 3. The motor control device 2 controls the motor 3 by controlling the current flowing from the power supply circuit 24 to the motor 3. As a method of controlling the current flowing through the motor 3, for example, PWM (Pulse Width Modulation) control is adopted. That is, the current controller 213 controls the operation of the switching element of the power supply circuit 24 by the PWM signal P1 generated based on the current target value Ir1 and the measured value I1. As a result, the current controller 213 controls the current flowing through the motor 3.

There is a correlation between the torque generated between the propeller 4 and the motor 3, the thrust generated by the propeller 4, and the rotation speed of the motor 3. The correlation between torque, thrust, and rotation speed changes due to the influence of the wind around the moving body 1. The torque generated between the propeller 4 and the motor 3 is, for example, proportional to the square of the rotation speed of the motor 3. The thrust generated by the propeller 4 is, for example, proportional to the square of the rotation speed of the motor 3. The motor control device 2 controls the rotation speed of the motor 3 by performing feedback control regarding torque and thrust.

The motor rotation measuring unit 23, the current sensor 25, and the pressure sensor 27 acquire information about the motor 3.

The motor rotation measuring unit 23 measures the rotation angle A1 of the motor 3. The motor rotation measuring unit 23 includes, for example, a photoelectric encoder or a magnetic encoder.

The current sensor 25 measures the current flowing through the motor 3. More specifically, the motor 3 is supplied with a three-phase current (U-phase current, V-phase current, and W-phase current) from the power supply circuit 24. The current sensor 25 measures at least two phases of current.

The pressure sensor 27 detects the pressure generated between the motor 3 and the propeller 4. The pressure sensor 27 receives an axial force generated by the rotation of the rotating shaft from the rotating shaft of the rotor of the motor 3 and detects this force. As the pressure sensor 27, for example, a resistance type strain gauge, a semiconductor type pressure sensor, or the like can be adopted. Examples of the semiconductor pressure sensor include a piezoresistive pressure sensor and a capacitance type pressure sensor.

The acquisition unit 26 calculates the d-axis current and the q-axis current flowing through the motor 3. More specifically, the acquisition unit 26 converts the currents of at least two phases measured by the current sensor 25 into coordinates based on the rotation angle A1 of the motor 3 measured by the motor rotation measurement unit 23, and performs a magnetic field component (d). It is converted into a current measurement value of (shaft current) and a current measurement value of a torque component (q-axis current). The torque detection value T1, which is a value corresponding to the torque generated between the propeller 4 and the motor 3, is a current measurement value of the torque component (q-axis current) calculated by the acquisition unit 26. That is, the acquisition unit 26 calculates the torque detection value T1 based on the current flowing through the motor 3. The relationship between the current of at least two phases detected by the current sensor 25 and the torque detection value T1 is stored in the memory of the motor control device 2 in the form of an arithmetic expression or a data table, for example.

The thrust calculation unit 28 calculates the thrust (thrust detection value F1) generated by the propeller 4 based on the detection value of the pressure generated between the motor 3 and the propeller 4 detected by the pressure sensor 27. The relationship between the pressure detection value and the thrust detection value F1 is stored in the memory of the motor control device 2 in the form of an arithmetic expression or a data table, for example. The larger the pressure detection value, the larger the thrust detection value F1 calculated by the thrust calculation unit 28.

The output unit 29 outputs the torque detection value T1. The output unit 29 outputs (stores), for example, the torque detection value T1 to the memory of the motor control unit 21. The output unit 29 has, for example, a wireless communication device, and outputs (transmits) a signal including the torque detection value T1 to the external device by wireless communication.

The control output unit 22 outputs information regarding the control content of the motor 3 by the motor control unit 21. The information regarding the control content of the motor 3 is, for example, a torque target value Tr1 and a thrust target value Fr1, and various other target values. The control output unit 22 outputs (stores), for example, information on the control content of the motor 3 to the memory of the motor control unit 21. The control output unit 22 has, for example, a wireless communication device, and outputs (transmits) information on the control content of the motor 3 to an external device by wireless communication. The control output unit 22 and the output unit 29 may share a part or all of the configuration.

(3) Operation Flow The operation flow of the motor control device 2 will be described with reference to FIG. FIG. 4 is a flowchart showing an operation example of the moving body according to the embodiment.

The current sensor 25 of the motor control device 2 measures the current flowing through the motor 3 (step ST1). The acquisition unit 26 calculates (acquires) a torque detection value T1 corresponding to the torque generated between the propeller 4 and the motor 3 based on the current measured by the current sensor 25 (step ST2). The pressure sensor 27 of the motor control device 2 detects the pressure generated between the motor 3 and the propeller 4 (step ST3). The thrust calculation unit 28 calculates the thrust detection value F1 based on the pressure detection value detected by the pressure sensor 27 (step ST4). The motor control unit 21 controls the motor 3 based on the torque detection value T1 and the thrust detection value F1 of the propeller 4 (step ST5). Such processing is executed by each of the four motor control devices 2.

(4) Summary Since the motor control device 2 described above controls the motor 3 based on the torque detection value T1, the motor 3 is controlled based on the detection results such as the posture and speed of the moving body 1. In comparison, the control responsiveness of the motor 3 can be improved.

Since the motor control device 2 further controls the motor 3 based on the thrust detection value F1, the accuracy of the control of the motor 3 is improved as compared with the case where the motor 3 is controlled only based on the torque detection value T1. be able to. Further, both the fluctuation of the torque detection value T1 and the fluctuation of the thrust detection value F1 can be detected before the fluctuation of the posture of the moving body 1 is detected by the gyro sensor. Therefore, the posture of the moving body 1 can be corrected by controlling the motor 3 based on the changed torque detection value T1 and the thrust detection value F1 before the posture of the moving body 1 collapses significantly.

If the torque detection value T1 and the thrust detection value F1 are calculated based on the rotation speed of the motor 3, the rotation speed of the motor 3 and the torque detection value T1 and the thrust detection value are affected by the influence of the wind around the moving body 1. The correlation with F1 may change and the calculation accuracy may deteriorate. In the motor control device 2, the torque detection value T1 is calculated based on the current measured by the current sensor 25. Further, the thrust detection value F1 is calculated based on the pressure detection value measured by the pressure sensor 27. Therefore, the influence of the wind on the torque detection value T1 and the thrust detection value F1 can be reduced. Therefore, the accuracy of control of the motor 3 can be improved.

(5) Modification 1
Hereinafter, the motor control device 2A according to the first modification of the embodiment will be described with reference to FIG. FIG. 5 is a block diagram of the motor control device of the moving body according to the first modification. The same components as those in the embodiment are designated by the same reference numerals and the description thereof will be omitted. In the following, one of the four motor control devices 2A will be described.

The motor control unit 21A of the modification 1 further includes a rotation speed controller 214. The torque / thrust control unit 210 generates a rotation speed target value Nr1 that indicates the rotation speed of the motor 3 based on the torque target value Tr1 and the thrust target value Fr1, and outputs the rotation speed target value Nr1 to the rotation speed controller 214. That is, in the torque / thrust control unit 210, the difference between the torque target value Tr1 and the torque detection value T1 converges within the first predetermined range, and the difference between the thrust target value Fr1 and the thrust detection value F1 is the second. The rotation speed target value Nr1 is set so as to converge within the predetermined range of.

The motor control unit 21A controls the rotation speed to control the current flowing through the motor 3 based on the rotation speed of the motor 3. More specifically, the rotation speed target value Nr1 is input to the rotation speed controller 214 from the torque / thrust control unit 210. The rotation speed A1 (measured value) of the motor 3 measured by the motor rotation measuring unit 23 is input to the rotation speed controller 214. The rotation speed controller 214 calculates the measured value of the rotation speed of the motor 3 by time-differentiating the rotation angle A1. The motor control unit 21A performs feedback control so that the measured value of the rotation speed approaches the rotation speed target value Nr1. That is, the rotation speed controller 214 determines the current target value Ir1 so that the difference between the measured rotation speed value and the rotation speed target value Nr1 converges within a predetermined range.

As described above, the motor control unit 21A controls the rotation speed to control the current flowing through the motor 3 based on the measured value of the rotation speed of the motor 3. Therefore, the accuracy of control of the motor 3 can be improved as compared with the case where the motor control unit 21A controls the motor 3 without using the measured value of the rotation speed of the motor 3. Further, also in the first modification, the control of the motor 3 can be changed according to the change of the torque detection value T1 or the thrust detection value F1. Therefore, the responsiveness of the control of the motor 3 can be improved as compared with the case where neither the torque detection value T1 nor the thrust detection value F1 is used for the control of the motor 3.

In the first modification, the rotation speed controller 214 may be provided in front of the torque / thrust control unit 210. That is, in one embodiment, the indicating unit 82 (see FIG. 2) of the middle unit 7 (see FIG. 2) calculates the rotation speed target value Nr1 based on the target values Tr, τφr, τθr, and τψr, and rotates. The numerical target value Nr1 is output to the rotation speed controller 214. The rotation speed controller 214 determines the torque target value Tr1 and the thrust target value Fr1 so that the difference between the rotation speed target value Nr1 and the measured value of the rotation speed of the motor 3 converges within a predetermined range. In the torque / thrust control unit 210, the difference between the torque target value Tr1 and the torque detection value T1 converges within the first predetermined range, and the difference between the thrust target value Fr1 and the thrust detection value F1 is the second predetermined value. The current target value Ir1 is set so as to converge within the range. Even with such a configuration, the motor control unit 21A can control the rotation speed based on the rotation speed of the motor 3.

(6) Other Modification Examples The other modifications of the embodiment are listed below. The following modifications may be realized in appropriate combinations.

At least a part of the same functions as the motor control device 2 and the mobile body 1 may be embodied in a motor control method, a (computer) program, a non-temporary recording medium on which the program is recorded, or the like.

The motor control method according to one aspect includes a first step of acquiring a torque detection value T1 corresponding to the torque generated between the propeller 4 and the motor 3 that rotates the propeller 4, and a torque acquired in the first step. A second step of controlling the motor 3 based on the detected value T1 is provided.

The program according to one aspect is a program for causing one or more processors to execute the above motor control method.

The motor control device 2 and the mobile body 1 in the present disclosure include a computer system. The main configuration of a computer system is a processor and memory as hardware. When the processor executes the program recorded in the memory of the computer system, at least a part of the functions as the motor control device 2 and the mobile body 1 in the present disclosure is realized. The program may be pre-recorded in the memory of the computer system, may be provided through a telecommunications line, and may be recorded on a non-temporary recording medium such as a memory card, optical disk, hard disk drive, etc. that can be read by the computer system. May be provided. The processor of a computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC, Integrated Circuit) or a large-scale integrated circuit (LSI, Large Scale Integration). The integrated circuit such as an IC or LSI referred to here has a different name depending on the degree of integration, and includes an integrated circuit called a system LSI, a VLSI (Very Large Scale Integration), or a ULSI (Ultra Large Scale Integration). Further, an FPGA (Field-Programmable Gate Array) programmed after manufacturing the LSI, or a logical device capable of reconfiguring the junction relationship inside the LSI or reconfiguring the circuit partition inside the LSI should also be adopted as a processor. Can be done. A plurality of electronic circuits may be integrated on one chip, or may be distributed on a plurality of chips. The plurality of chips may be integrated in one device, or may be distributed in a plurality of devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

It is not an essential configuration for the motor control device 2 and the mobile body 1 that a plurality of functions of the motor control device 2 and the mobile body 1 are integrated in one housing. The components of the motor control device 2 and the moving body 1 may be dispersedly provided in a plurality of housings. Further, at least a part of the functions of the motor control device 2 and the mobile body 1, for example, a part of the functions of the acquisition unit 26 may be realized by a cloud (cloud computing) or the like.

On the contrary, in the embodiment, at least a part of the functions of the motor control device 2 and the moving body 1 distributed in a plurality of devices may be integrated in one housing. For example, some functions of the motor control device 2 and the moving body 1 dispersed in the middle portion 7 and the motor control device 2 may be integrated in one housing.

The motor control unit 21 may perform voltage control for controlling the voltage applied to the motor 3 based on the voltage applied to the motor 3. Specifically, the voltage applied to the motor 3 is a voltage applied to the winding of the motor 3. In one aspect when the motor control unit 21 performs voltage control, the voltage sensor of the moving body 1 acquires the voltage detection value of the voltage applied to the motor 3. The motor control unit 21 includes a voltage controller instead of the current controller 213. The torque / thrust control unit 210 transmits a voltage instruction signal including a target value (voltage target value) of the voltage applied to the motor 3 to the voltage controller. The voltage controller controls the operation of the switching element of the power supply circuit 24 so that the difference between the voltage target value and the voltage detection value converges within a predetermined range. As a result, the voltage controller controls the current flowing through the motor 3. In other words, the motor control unit 21 performs feedback control so that the voltage detection value approaches the voltage target value.

The motor control unit 21 does not control the motor 3 based on both the torque detection value T1 and the thrust detection value F1, but controls the motor 3 based on one of the torque detection value T1 and the thrust detection value F1. May be good.

The mobile body 1 is not limited to a drone (aerial drone), and may be, for example, a radio-controlled aircraft. The mobile body 1 is not limited to a flying body such as a drone and a radio-controlled aircraft. The moving body 1 may be a device that moves on or under water, such as a water drone, an underwater drone, a water radio control, or a submarine radio control (underwater radio control).

The number of propellers 4 and the number of motors 3 included in the moving body 1 are not limited to four. The number of propellers 4 and the number of motors 3 of the moving body 1 may be, for example, two, three, six, or eight.

The number of motor control devices 2 included in the moving body 1 is not limited to four. Further, the number of motor control devices 2 may be different from the number of propellers 4 and the number of motors 3. One motor control device 2 may control a plurality of motors 3.

In each motor control device 2, information about the motor 3 to be controlled is acquired by each sensor (motor rotation measuring unit 23, current sensor 25, and pressure sensor 27). In the embodiment, each motor control device 2 controls the motor 3 by using only the information about the motor 3 to be controlled among the information about the plurality of motors 3. On the other hand, each motor control device 2 further uses the information about the motor 3 other than the motor 3 to be controlled in addition to the information about the motor 3 to be controlled among the plurality of motors 3, and the motor 3 to be controlled. May be controlled.

A part of the configuration may be shared between the plurality of motor control devices 2. For example, at least a part of the output unit 29, the control output unit 22, the acquisition unit 26, and the thrust calculation unit 28 may be shared among the plurality of motor control devices 2.

The motor control device 2 may include at least an acquisition unit 26 and a motor control unit 21. For example, the current sensor 25 and the pressure sensor 27 may be provided in the moving body 1 as an external configuration of the motor control device 2.

The acquisition unit 26 is not limited to the configuration in which the torque detection value T1 is calculated by itself. For example, when the moving body 1 includes a calculation unit for calculating the torque detection value T1 as an external configuration of the motor control device 2, the acquisition unit 26 may acquire the torque detection value T1 from the calculation unit. ..

The moving body 1 may be provided with a torque sensor. The acquisition unit 26 may calculate the torque detection value T1 based on the output of the torque sensor instead of the output of the current sensor 25. The torque sensor referred to here measures the operating torque of the motor 3. The torque sensor is, for example, a magnetostrictive strain sensor capable of detecting torsional strain. The magnetostrictive strain sensor detects a change in magnetic permeability according to the strain generated by applying torque to the rotating shaft of the motor 3 with a coil installed in the non-rotating part of the motor 3, and outputs a voltage signal proportional to the strain. Output.

The operation of the motor control unit 21 based on the torque detection value T1 is not limited to the feedback control that causes the torque detection value T1 to approach the torque target value. The operation of the motor control unit 21 based on the thrust detection value F1 is not limited to the feedback control that causes the thrust detection value F1 to approach the thrust target value. The motor control unit 21 causes the torque detection value T1 and the thrust detection value F1 to elapse over time in order to cause the moving body 1 to crash land when, for example, the wind speed around the moving body 1 exceeds a threshold value. Control may be performed to reduce the rotation speed of the motor 3 so as to decrease in accordance with the above. The term "reducing the rotation speed of the motor 3" as used herein includes setting the rotation speed of the motor 3 to 0 (that is, stopping the motor 3). The wind speed around the moving body 1 may be detected by, for example, a wind speed sensor provided in the moving body 1.

The motor control unit 21 may set a limit value of the torque detection value T1 when a specific condition is satisfied. When the torque target value is larger than the limit value, the motor control unit 21 may control the motor 3 so that the torque detection value T1 approaches the limit value instead of the torque target value. When the specific condition is not satisfied, the motor control unit 21 cancels the setting of the limit value. As a result, there is room for increasing the torque of the motor 3 when a specific condition is not satisfied, so that the flexibility of control of the motor 3 can be increased. For example, when a specific condition that the moving body 1 enters the turbulence is satisfied, a limit value is set, and after the moving body 1 escapes from the eddy, the limit value setting is released and the torques of the four motors 3 Can be appropriately increased or decreased for each motor 3 to correct the posture of the moving body 1. Similarly, the motor control unit 21 may set a limit value of the thrust detection value F1 when a specific condition is satisfied. Whether or not the moving body 1 has entered the turbulent airflow may be determined based on, for example, the detection result of the air flow sensor provided in the moving body 1. The air flow sensor detects the wind speed and the wind direction around the moving body 1.

The motor control unit 21 may further control the motor 3 based on the output of the gyro sensor of the motion detection unit 9. For example, the motor control unit 21 determines the magnitude of the posture disturbance of the moving body 1 based on the torque detection value T1. When the motor control unit 21 determines that the magnitude of the posture disturbance of the moving body 1 exceeds a predetermined value based on the torque detection value T1, the motor control unit 21 first controls the motor 3 based on the torque detection value T1. After that, when a predetermined time elapses, the motor control unit 21 controls the motor 3 based on the output of the gyro sensor among the torque detection value T1 and the gyro sensor. In short, when the motor control unit 21 detects the disorder of the posture of the moving body 1 based on the torque detection value T1, the motor control unit 21 first corrects the posture based on the torque detection value T1. After that, after the timing when the posture disorder is reflected in the output of the gyro sensor, the motor control unit 21 corrects the posture based on the output of the gyro sensor. Thereby, the accuracy of control for the motor 3 can be improved.

(7) Summary The following aspects are disclosed from the above-described embodiments and the like.

The motor control device (2, 2A) according to the first aspect includes an acquisition unit (26) and a motor control unit (21, 21A). The acquisition unit (26) acquires a torque detection value (T1) corresponding to the torque generated between the propeller (4) and the motor (3) that rotates the propeller (4). The motor control units (21, 21A) control the motor (3) based on the torque detection value (T1) acquired by the acquisition unit (26).

According to the above configuration, after the change in torque generated between the propeller (4) and the motor (3), before the attitude, speed, etc. of the moving body (1) change as a result of the change in torque. Even so, the control of the motor (3) can be changed based on the changed torque detection value (T1). Therefore, the responsiveness of the control of the motor (3) can be improved as compared with the case where the motor (3) is controlled based on the detection result of the posture and speed of the moving body (1).

Further, in the motor control device (2, 2A) according to the second aspect, in the first aspect, the motor control unit (21, 21A) has a thrust detection value (F1) corresponding to the thrust generated by the propeller (4). ) Further, the motor (3) is controlled.

According to the above configuration, the accuracy of control of the motor (3) is improved as compared with the case where the motor control units (21, 21A) control the motor (3) based only on the torque detection value (T1). be able to.

Further, in the motor control device (2, 2A) according to the third aspect, in the first or second aspect, the motor control unit (21, 21A) performs current control. In the current control, the motor control units (21, 21A) control the current flowing through the motor (3) based on the current flowing through the motor (3).

According to the above configuration, the accuracy of control of the motor (3) is improved as compared with the case where the motor control units (21, 21A) control the motor (3) based only on the torque detection value (T1). be able to.

Further, in the motor control device (2, 2A) according to the fourth aspect, in the first or second aspect, the motor control unit (21, 21A) performs voltage control. In voltage control, the motor control units (21, 21A) control the voltage applied to the motor (3) based on the voltage applied to the motor (3).

According to the above configuration, the accuracy of control of the motor (3) is improved as compared with the case where the motor control units (21, 21A) control the motor (3) based only on the torque detection value (T1). be able to.

Further, in the motor control device (2A) according to the fifth aspect, the motor control unit (21A) controls the rotation speed in any one of the first to fourth aspects. In the rotation speed control, the motor control unit (21A) controls the current flowing through the motor (3) based on the rotation speed of the motor (3).

According to the above configuration, the accuracy of control of the motor (3) can be improved as compared with the case where the motor control unit (21A) controls the motor (3) based only on the torque detection value (T1). it can.

Further, in the motor control device (2, 2A) according to the sixth aspect, in any one of the first to fifth aspects, the motor control unit (21, 21A) has a torque detection value (T1) as a torque target. Feedback control is performed so as to approach the value (Tr1).

According to the above configuration, the accuracy of control of the motor (3) can be improved.

Further, the motor control device (2, 2A) according to the seventh aspect further includes an output unit (29) in any one of the first to sixth aspects. The output unit (29) outputs the torque detection value (T1).

According to the above configuration, the torque detection value (T1) can be used outside the motor control device (2, 2A). For example, an external device of the motor control device (2, 2A) can determine the operating state of the motor (3) by monitoring the torque detection value (T1) output from the output unit (29). ..

Further, the motor control device (2, 2A) according to the eighth aspect further includes a control output unit (22) in any one of the first to seventh aspects. The control output unit (22) outputs information regarding the control content of the motor (3) by the motor control unit (21, 21A).

According to the above configuration, the user or the like can grasp the control content of the motor (3).

Further, in the motor control device (2, 2A) according to the ninth aspect, in any one of the first to eighth aspects, the acquisition unit (26) torques based on the current flowing through the motor (3). The detected value (T1) is calculated.

According to the above configuration, the torque detection value (T1) can be calculated without using a torque sensor such as a magnetostrictive strain sensor.

Configurations other than the first aspect are not essential configurations for the motor control device (2, 2A) and can be omitted as appropriate.

Further, the moving body (1) according to the tenth aspect includes a motor control device (2, 2A), a motor (3), a propeller (4), and the propeller (4) according to any one of the first to ninth aspects. It includes a moving body main body (5). A motor (3), a propeller (4), and a motor control device (2, 2A) are mounted on the mobile body (5).

According to the above configuration, the responsiveness of the control of the motor (3) can be improved.

Further, the moving body (1) according to the eleventh aspect includes three or more motors (3) and propellers (4) in the tenth aspect.

Further, in the motor control method according to the twelfth aspect, the first method of acquiring a torque detection value (T1) corresponding to the torque generated between the propeller (4) and the motor (3) for rotating the propeller (4). And a second step of controlling the motor (3) based on the torque detection value (T1) acquired in the first step.

According to the above configuration, the responsiveness of the control of the motor (3) can be improved.

Further, the program according to the thirteenth aspect is a program for causing one or more processors to execute the motor control method according to the twelfth aspect.

Not limited to the above aspects, various configurations (including modifications) of the motor control device (2, 2A) and the moving body (1) according to the embodiment can be embodied by a motor control method and a program.

1 Moving body 2, 2A Motor control device 21, 21A Motor control unit 210 Torque / thrust control unit 211 Torque controller 212 Thrust controller 213 Current controller 214 Rotation speed controller 22 Control output unit 23 Motor rotation measurement unit 24 Power supply circuit 25 Current sensor 26 Acquisition unit 27 Pressure sensor 28 Propulsion calculation unit 29 Output unit 3 Motor 4, 41, 42, 43, 44 Propeller 5 Mobile body 51 Arm 6 Upper part 7 Middle part 71 Advanced controller 72, 73 Position control Instrument 74, 75 Speed controller 76, 77, 78 Angle controller 79, 80, 81 Angle speed controller 82 Indicator 9 Motion detector

Claims (13)

1. It includes an acquisition unit that acquires a torque detection value corresponding to the torque generated between the propeller and the motor that rotates the propeller, and a motor control unit that controls the motor based on the torque detection value.
   Motor control device.
2. The motor control unit further controls the motor based on a thrust detection value corresponding to the thrust generated by the propeller.
   The motor control device according to claim 1.
3. The motor control unit performs current control for controlling the current flowing through the motor based on the current flowing through the motor.
   The motor control device according to claim 1 or 2.
4. The motor control unit performs voltage control for controlling the voltage applied to the motor based on the voltage applied to the motor.
   The motor control device according to claim 1 or 2.
5. The motor control unit controls the rotation speed to control the current flowing through the motor based on the rotation speed of the motor.
   The motor control device according to any one of claims 1 to 4.
6. The motor control unit feedback-controls the torque detection value so that it approaches the torque target value.
   The motor control device according to any one of claims 1 to 5.
7. The motor control device according to any one of claims 1 to 6, further comprising an output unit that outputs the torque detection value.
8. A control output unit that outputs information regarding the control content of the motor by the motor control unit is further provided.
   The motor control device according to any one of claims 1 to 7.
9. The acquisition unit calculates the torque detection value based on the current flowing through the motor.
   The motor control device according to any one of claims 1 to 8.
10. The motor control device according to any one of claims 1 to 9,
    With the motor
    With the propeller
    A mobile body including the motor, the propeller, and the motor control device.
    Mobile body.
11. Each of the motor and the propeller is provided with three or more.
    The moving body according to claim 10.
12. The first step of acquiring a torque detection value corresponding to the torque generated between the propeller and the motor that rotates the propeller, and
    A second step of controlling the motor based on the torque detection value acquired in the first step is provided.
    Motor control method.
13. A method for causing one or more processors to execute the motor control method according to claim 12.
    program.

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