JP2014168967A - Handcart - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a handcart capable of decelerating during overspeed time while performing inverted pendulum control.SOLUTION: A speed limit determination part 212 sets a target inclined angle of a target inclined angle set part 213 according to angular speed of a main wheel 11. In other words, the speed limit determination part 212 sets the target inclined angle to a first angle when the angular speed of the main wheel 11 is equal to or less than the predetermined threshold (first control mode). The speed limit determination part 212 sets the target inclined angle to a second angle when the angular speed of the main wheel 11 is more than the predetermined threshold (second control mode). Although, a position of a body 10 in the second control mode is set so as to be an opposed direction to a travel direction with respect to the position of the body 10 in the first control mode.

Description

  The present invention relates to a handcart that includes wheels and that drives and controls the wheels.

  Conventionally, as shown in Japanese Patent Application Laid-Open No. 2004-133620, there is a technique for slowing down a wheelbarrow by loosening a motor output with respect to a pushing force in a traveling direction when the speed is exceeded.

No. 98-041182

  However, in the handcart using the inverted pendulum control, if the motor output is loosened, the inverted pendulum control itself may be affected.

  In addition, although a general walking assistance vehicle has a manual brake, there are cases where elderly people with reduced grip strength cannot perform the braking operation in the first place.

  Accordingly, an object of the present invention is to provide a handcart that decelerates when the speed is exceeded while performing inverted pendulum control.

  The wheelbarrow of the present invention includes a wheel, a main body that rotatably supports the wheel, a drive control unit that drives and controls the wheel, a speed sensor that detects a moving speed of the main body, and the main body. Angle change detecting means for detecting the angle change of the inclination angle of the pitch direction of the part.

  The drive control unit includes a first control mode for controlling rotation of the wheel so that an angle change of the main body unit becomes 0 and an inclination angle of the main body unit with respect to a vertical direction becomes a first angle; and the speed sensor When the movement speed detected by the unit exceeds a predetermined threshold, the drive control unit is configured such that the change in the angle of the main unit is 0 and the inclination angle of the main unit with respect to the vertical direction is the second angle. And a second control mode for controlling the rotation of the wheel.

  In the handcart of the present invention, the position of the main body in the second control mode is opposite to the traveling direction of the main body with respect to the position of the main body in the first control mode. Features.

  As described above, the wheelbarrow of the present invention performs the inverted pendulum control by tilting the main body portion in the direction opposite to the traveling direction at the time of overspeed, which is opposite to the direction in which the user pushes the wheelbarrow. A force is applied in the direction, and the user can decelerate the force by pushing the wheelbarrow.

  Moreover, the threshold value serving as a reference for excess speed may be different depending on the traveling direction of the main body. For example, the threshold value for backward travel is set lower than that for forward travel. The threshold value may be manually adjusted by the user.

  The angle change detection means may use a pitch angle sensor (inclination angle sensor) that detects an angle change of the inclination angle of the main body portion in the pitch direction, and one end is connected to the main body portion and rotates in the pitch direction. In the case of having a supporting part capable of rotating and an auxiliary wheel rotatably supported at the other end of the supporting part, the crossing angle of the main body part and the supporting part is detected, and the inclination angle of the main body part from the crossing angle May be estimated.

  Note that when the user releases his / her hand from the main body, the first control mode may be restored.

  According to this invention, it is possible to decelerate when the speed is exceeded while performing inverted pendulum control.

It is an external view of a wheelbarrow. It is a control block diagram which shows the structure of a handcart. 3 is a block diagram of a control unit 21. FIG. It is the figure which showed the relationship between angular velocity and a target inclination angle. It is a block diagram of control part 21 concerning a modification. It is a figure which shows the relationship between a ground inclination angle, a main body inclination angle, and a crossing angle. It is a control block diagram which shows the structure of the handcart 1B provided with the touch sensor. 3 is a block diagram of a control unit 21. FIG.

  FIG. 1 is an external view of a handcart 1 that is an embodiment of the moving body of the present invention. FIG. 2 is a control configuration diagram showing the configuration of the handcart 1.

  The handcart 1 includes, for example, a rectangular parallelepiped main body 10. The main body 10 has a shape that is long in the vertical direction (Z and −Z directions in the drawing) and short in the depth direction (Y and −Y directions in the drawing). The main body 10 incorporates a control board, a battery, and the like inside.

  Of the lower part of the main body 10 in the vertically downward direction (−Z direction), a main wheel 11 is attached to an end portion on the right side (X direction in the drawing) and an end portion on the left side (−X direction in the drawing). . The pair of main wheels 11 are independently attached to the drive shaft and rotate synchronously. However, these main wheels 11 can be individually driven and rotated. Moreover, in this embodiment, although the main wheel 11 has shown the example which is two wheels, it is not restricted to two wheels.

For example, one end of a cylindrical handle 15 is attached to the upper part of the main body 10 in the vertical direction, and a T-shaped grip 16 is attached to the other end of the handle 15. The grip portion 16 is provided with a user interface such as a power switch (user I / F 28 shown in FIG. 2). A manual brake 29 is attached to the handle 15 at a position close to the grip portion 16 (the manual brake is not an essential component in the present invention). The user can grip the grip portion 16 or place a forearm or the like on the grip portion 16 and press the handcart 1 by friction between the grip portion and the forearm.
The main body 10 is actually provided with a cover so that the internal substrate and the like cannot be seen in appearance.

  One end of a rod-shaped support portion 12 is attached to the back surface (−Y direction) of the main body portion 10. One end of the support portion 12 is rotatably connected to the main body portion 10. An auxiliary wheel 13 is attached to the other end of the support portion 12. The support part 12 supports the main body part 10 and prevents the main body part 10 from overturning. In addition, although the support part 12 and the auxiliary | assistant wheel 13 are not essential structures in this invention, even when the main-body part 10 will be in the state largely inclined from the perpendicular direction at the time of power-off by providing the auxiliary | assistant wheel 13, By pushing the main wheel 11 and the auxiliary wheel 13 to the ground, the handcart 1 can be pushed. Moreover, the support part 12 and the auxiliary wheel 13 may be two or more.

  Next, the configuration and basic operation of the handcart 1 will be described. As shown in FIG. 2, the handcart 1 includes an inclination angle sensor 20, a control unit 21, a ROM 22, a RAM 23, a gyro sensor 24, a main wheel drive unit 25, a main wheel rotary encoder 26, a support unit rotary encoder 27, and a user. An I / F 28 and a manual brake 29 are provided.

  The control unit 21 is a functional unit that comprehensively controls the handcart 1, and reads out a program stored in the ROM 22 and develops the program in the RAM 23 to realize various operations. The tilt angle sensor 20 detects the tilt angle with respect to the vertical direction in the pitch direction of the main body 10 (the rotation direction about the axis of the main wheel 11 in FIG. 1), and outputs the detected tilt angle to the control unit 21. The gyro sensor 24 detects the angular velocity in the pitch direction of the main body unit 10 and outputs it to the control unit 21. The handcart 1 may further include an acceleration sensor that detects acceleration in each direction of the main body 10, a rotary encoder that detects the rotation angle of the auxiliary wheel 13, and the like.

  The main wheel rotary encoder 26 detects the rotation angle of the main wheel 11 and outputs the detection result to the control unit 21. The support unit rotary encoder 27 detects an intersection angle that is an angle formed by the main body unit 10 and the support unit 12, and outputs a detection result to the control unit 21.

  As a basic operation, the control unit 21 detects a change in the tilt angle of the main body 10 in the pitch direction based on the detection results of the gyro sensor 24 and the tilt angle sensor 20, and the angle change in the pitch direction of the main body 10 is zero. The main wheel drive unit 25 is controlled so that the inclination angle of the main body 10 with respect to the vertical direction becomes a target value (for example, 0 or a value close to 0).

  FIG. 3 is a block diagram of the control unit 21. The control unit 21 includes a main wheel speed detection unit 211, a speed limit determination unit 212, a target tilt angle setting unit 213, a tilt angle detection unit 214, a main body tilt angle controller 215, a tilt angular velocity detection unit 216, and a main body tilt angular velocity. A controller 217 is provided.

  The main wheel speed detection unit 211 differentiates the rotation angle of the main wheel 11 input from the main wheel rotary encoder 26 to calculate the angular speed of the main wheel 11.

  The tilt angle detection unit 214 calculates the tilt angle of the main body 10 based on the detection result of the tilt angle sensor 20 (for example, performs a low-pass filter process).

  The tilt angular velocity detection unit 216 calculates the tilt angular velocity of the main body 10 based on the detection result of the gyro sensor 24 (for example, performs a low-pass filter process).

  The main body inclination angle controller 215 is a difference between the target inclination angle (for example, 0 degree) input from the target inclination angle setting section 213 and the current inclination angle of the main body section 10 input from the inclination angle detection section 214. A value is input, and the tilt angular velocity of the main body 10 is calculated so that the difference value becomes zero. The main body tilt angular velocity controller 217 inputs a difference value between the tilt angular velocity calculated by the main body tilt angle controller 215 and the current tilt angular velocity of the main body 10 input from the tilt angular velocity detector 216. Then, a torque value is calculated such that the difference value becomes zero.

  The torque value calculated by the main body tilt angular velocity controller 217 is input to the main wheel drive unit 25. The main wheel drive unit 25 is a functional unit that drives a motor that rotates a shaft attached to the main wheel 11, and applies an input torque value to the motor of the main wheel 11 to rotate the main wheel 11.

  In this way, the handcart 1 performs the inverted pendulum control, and performs control so as to keep the posture of the main body unit 10 constant. Thereby, the handcart 1 can maintain a fixed posture even when the user holds the grip portion 16 and pushes the handcart 1.

  In the handcart 1 of the present embodiment, the speed limit determination unit 212 sets the target tilt angle of the target tilt angle setting unit 213 according to the angular speed of the main wheel 11. That is, the speed limit determination unit 212 sets the target tilt angle of the target tilt angle setting unit 213 to a first angle (for example, the above 0 degree) when the angular velocity of the main wheel 11 is equal to or less than a predetermined threshold (first degree). 1 control mode). Further, when the angular velocity of the main wheel 11 exceeds a predetermined threshold, the speed limit determination unit 212 sets the target tilt angle of the target tilt angle setting unit 213 to the second angle (second control mode). However, the position of the main body 10 in the second control mode is set to be opposite to the traveling direction with respect to the position of the main body 10 in the first control mode.

  FIG. 4 is a diagram showing the relationship between the angular velocity of the main wheel 11 and the target inclination angle. In the figure, the positive angular velocity indicates the direction in which the main wheel 11 rotates clockwise as viewed from the right side of the main body 10. Further, the positive inclination angle indicates a direction in which the main body 10 rotates clockwise as viewed from the right side of the main body 10. That is, when the tilt angle is positive, the main body portion 10 tilts forward with respect to the traveling direction, and when the tilt angle is negative, the main body portion 10 tilts backward with respect to the traveling direction.

  In the example of FIG. 4A, when the angular velocity of the main wheel 11 is −6π to + 6π (rad / s), the target inclination angle is set to 0 degree, and the angular velocity of the main wheel 11 is −6π (rad / s). The target inclination angle is set to + π / 8 (rad) when the angle is less than, and the target inclination angle is set to −π / 8 (rad) when the angular velocity of the main wheel 11 exceeds + 6π (rad / s). Is done.

  That is, when the speed at which the wheelbarrow 1 moves forward increases to some extent, the main body 10 tilts backward. Accordingly, a force is applied in the direction opposite to the direction in which the user pushes the handcart (backward), and the user can decelerate the force by pushing the handcart. Similarly, when the reverse speed of the handcart 1 is increased to some extent, the main body 10 is inclined forward. As a result, a force is applied in the opposite direction (forward) to the direction in which the user pulls the handcart, and the user can weaken the force to pull the handcart and decelerate. Even in these second control modes, since the inverted pendulum control is continuously performed, the function as a handcart is maintained.

  Further, as shown in FIG. 4B, the threshold value may be different between forward and reverse. In the example of FIG. 4B, when the angular velocity of the main wheel 11 is −4π to + 6π (rad / s), the target inclination angle is set to 0 degree, and the angular velocity of the main wheel 11 is −4π (rad / s). The target inclination angle is set to + π / 8 (rad) when the angle is less than, and the target inclination angle is set to −π / 8 (rad) when the angular velocity of the main wheel 11 exceeds + 6π (rad / s). Is done. Accordingly, when the vehicle is moving backward, the target inclination angle changes at a lower moving speed than when moving forward, so that the moving speed can be further suppressed.

  Further, as shown in FIG. 4C, the target inclination angle may be different between forward travel and reverse travel. In the example of FIG. 4C, when the angular velocity of the main wheel 11 is less than −4π (rad / s), the target inclination angle is set to + π / 7 (rad), and the angular velocity of the main wheel 11 is + 6π ( When it exceeds (rad / s), the target inclination angle is set to -π / 8 (rad). Therefore, when moving backward, the vehicle is greatly inclined forward, and the moving speed can be further suppressed than when moving forward.

  Further, as shown in FIG. 4D, the inclination with respect to the vertical direction may be increased as the moving speed increases. In the example of FIG. 4D, when the angular velocity of the main wheel 11 is −4π to + 4π (rad / s), the target inclination angle is set to 0 degree, and the angular velocity of the main wheel 11 is −6π to −4π (rad). / S), the target inclination angle is set to + π / 12 (rad), and when the angular velocity of the main wheel 11 is less than −6π (rad / s), the target inclination angle is set to + π / 8 (rad). The When the angular velocity of the main wheel 11 is + 4π to + 6π (rad / s), the target inclination angle is set to −π / 12 (rad), and the angular velocity of the main wheel 11 is + 6π to + 8π (rad / s). The target inclination angle is set to -π / 8 (rad), and the target inclination angle is set to -π / 6 (rad) when the angular velocity of the main wheel 11 exceeds + 8π (rad / s). In this case, as the moving speed increases, the main body portion 10 is largely inclined in the reverse direction with respect to the traveling direction, so that the effect of suppressing the speed is increased.

  Note that the threshold value may be changed manually by accepting a user operation by the user I / F 28.

  In the above-described embodiment, the example using the inclination angle sensor 20 and the gyro sensor 24 as the means for detecting the angle change of the inclination angle in the pitch direction of the main body 10 has been described. However, as long as at least one of them is provided. Good. When only the tilt angle sensor 20 is provided, the tilt angle velocity of the main body 10 is calculated by differentiating the tilt angle of the main body 10 detected by the tilt angle sensor 20. When only the gyro sensor 24 is provided, the tilt angle of the main body 10 is calculated by integrating the tilt angular velocity of the main body 10 detected by the gyro sensor 24. Further, an acceleration sensor can be used, and any other sensor may be used.

  It is also possible to calculate the tilt angle of the main body 10 from the crossing angle between the main body 10 and the support 12 input from the support rotary encoder 27.

  FIG. 5 is a block diagram of the control unit 21 according to the modification. 3 is different from the example shown in FIG. 3 in that the inclination angle detection unit 214 is an inclination angle detection unit 214A. Components that are the same as those in FIG. 3 are given the same reference numerals, and descriptions thereof are omitted.

  In this modification, the tilt angle detection unit 214A estimates the tilt angle of the main body 10 from the intersection angle between the main body 10 and the support 12 input from the support rotary encoder 27.

  For example, as shown in FIG. 6, the intersection angle between the main body 10 and the support 12 is θ1, the inclination angle of the main body 10 with respect to the direction perpendicular to the ground is θ2, and the length of the main body 10 (the main body 10 and the support 12 L1 is the length from the intersection position of the main wheel 11 to L1 and the length of the support portion 12 (the length from the intersection position of the main body portion 10 and the support portion 12 to the auxiliary wheel 13) is L2, L1 cos θ2 = L2 cos ( From the relationship of θ1-θ2), the inclination angle θ2 of the main body 10 with respect to the direction perpendicular to the ground is

  It can be calculated by the following formula. In this way, it is possible to calculate the tilt angle of the main body 10 from the intersection angle between the main body 10 and the support 12 input from the support rotary encoder 27 and to perform the inverted pendulum control.

  Next, FIG. 7 is a control configuration diagram illustrating a configuration of the handcart 1B including the touch sensor, and FIG. 8 is a block diagram of the control unit 21 in the handcart 1B. The handcart 1B is further provided with a touch sensor 30 that detects whether or not a human body is touching the main body 10 with respect to the handcart 1 shown in FIG. In FIG. 7, the same components as those in FIG. In FIG. 8, the same components as those in FIG. 3 are denoted by the same reference numerals, and description thereof is omitted.

  The touch sensor 30 is provided, for example, in the grip portion 16 so that when the user grips the grip portion 16 or places a forearm or the like on the grip portion 16, it can detect that a human body has come into contact.

  In this example, as illustrated in FIG. 8, the target inclination angle setting unit 213 </ b> A inputs a detection result from the touch sensor 30, and the first control mode (the target inclination angle is 0 degree) according to the detection result of the touch sensor. Or the state near 0 degree) and the second control mode (state inclined with respect to the vertical direction) are switched. That is, when the target inclination angle setting unit 213A detects from the touch sensor 30 that the human body is not in contact, the target inclination angle is set even when the angular velocity of the main wheel 11 exceeds a predetermined threshold. Is set to the first angle (0 degrees or near 0 degrees).

  As a result, when the user presses the handcart 1B at a high speed, when the hand is released, the inclination angle of the main body 10 immediately returns to near 0 degrees. It is possible to prevent hitting the user's body.

DESCRIPTION OF SYMBOLS 1 ... Wheelbarrow 10 ... Main-body part 11 ... Main wheel 12 ... Support part 13 ... Auxiliary wheel 15 ... Handle 16 ... Grip part 20 ... Inclination angle sensor 21 ... Control part 22 ... ROM
23 ... RAM
24 ... Gyro sensor 25 ... Main wheel drive unit 26 ... Main wheel rotary encoder 27 ... Support unit rotary encoder 28 ... User I / F
29 ... Manual brake 30 ... Touch sensor 211 ... Main wheel speed detection unit 212 ... Speed limit determination unit 213 ... Target tilt angle setting unit 214 ... Inclination angle detection unit 215 ... Main body tilt angle controller 216 ... Inclination angular velocity detection unit 217 ... Main body tilt angular velocity controller

When the movement speed detected by the speed sensor unit is equal to or less than a predetermined threshold, the drive control unit has an angle change of the main body unit of 0, and an inclination angle of the main body unit with respect to the vertical direction is a first angle. When the first control mode for controlling the rotation of the wheel and the moving speed detected by the speed sensor unit exceed a predetermined threshold, the drive control unit changes the angle of the main body unit to 0, and And a second control mode for controlling the rotation of the wheel so that the inclination angle of the main body with respect to the vertical direction becomes a second angle.

Claims (8)

Wheels,
A main body that rotatably supports the wheel;
A drive controller for driving and controlling the wheels;
A speed sensor for detecting the moving speed of the main body,
An angle change detecting means for detecting an angle change of an inclination angle in the pitch direction of the main body, and a handcart having:
The drive control unit has a first control mode for controlling rotation of the wheel so that an angle change of the main body unit is 0 and an inclination angle of the main body unit with respect to a vertical direction is a first angle;
When the moving speed detected by the speed sensor unit exceeds a predetermined threshold, the drive control unit determines that the angle change of the main body unit is 0, and the inclination angle of the main body unit with respect to the vertical direction is the second angle. A second control mode for controlling the rotation of the wheel so that
Have
The handcart characterized in that the position of the main body in the second control mode is opposite to the traveling direction of the main body with respect to the position of the main body in the first control mode.   The handcart according to claim 1, wherein a threshold value of the moving speed is different depending on a traveling direction of the main body.   The handcart of Claim 1 or Claim 2 which has a threshold value adjustment means to adjust the threshold value of the said moving speed. The angle change detecting means includes a pitch angle sensor that detects an inclination angle of the main body portion in a pitch direction,
The handcart according to any one of claims 1 to 3, wherein the drive control unit performs control based on the pitch angle sensor. One end connected to the main body, and a support capable of rotating in the pitch direction;
The handcart according to any one of claims 1 to 4, further comprising an auxiliary wheel rotatably supported at the other end of the support portion. The angle change detecting means includes a crossing angle detecting means for detecting a crossing angle between the main body part and the support part,
The handcart according to claim 5, wherein the drive control unit performs control based on the intersection angle detection unit. The angle change detection means includes a pitch angular velocity sensor that detects an inclination angular velocity in the pitch direction of the main body,
The handcart according to any one of claims 1 to 6, wherein the drive control unit performs control based on the pitch angular velocity sensor. A touch sensor that detects whether or not a human body is touching the main body part is provided in a part of the main body part,
8. The manual push according to claim 1, wherein the drive control unit switches between the first control mode and the second control mode in accordance with an output of the touch sensor. car.

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