Dolly

Abstract

To provide a technology which can restrain a user from being swung around when a dolly carries out a swivel action.SOLUTION: A dolly disclosed by the present specifications may comprise a vehicle body, wheels supported by the vehicle body to come in contact with the ground, a motor which drives the wheels, a handle gripped by a user walking rearward of the vehicle body, and a control unit which controls the action of the mover. The control unit may, when carrying out a swivel action, set a target vehicle body speed on the swivel action when a swivel radius of the vehicle body is smaller than when the swivel radius of the vehicle body is large.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The technology disclosed herein relates to a transport vehicle. [Background technology]

[0002] Patent Document 1 discloses a transport vehicle. The transport vehicle includes a vehicle body, wheels supported by the vehicle body and in contact with the ground, a prime mover that drives the wheels, a handle that is held by a user standing behind the vehicle body, and a control unit that controls the operation of the prime mover. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-78708 A Summary of the Invention [Problem to be solved by the invention]

[0004] When the transport vehicle performs a turning operation, a user holding the handle and walking behind the vehicle body moves faster than the vehicle body. In particular, the smaller the turning radius of the vehicle body, the faster the user holding the handle and walking behind the vehicle body moves compared to the vehicle body. For this reason, when the transport vehicle performs a turning operation, the user may be swung around. This specification provides a technology that can suppress the user from being swung around when the transport vehicle performs a turning operation. [Means for solving the problem]

[0005] The transport vehicle disclosed in the present specification may include a vehicle body, wheels supported by the vehicle body and in contact with the ground, a prime mover for driving the wheels, a handle held by a user walking behind the vehicle body, and a control unit for controlling the operation of the prime mover. When the transport vehicle performs a turning operation, the control unit may set a target vehicle body speed during the turning operation to be smaller when the turning radius of the vehicle body is small compared to when the turning radius of the vehicle body is large.

[0006] According to the above configuration, when the transport vehicle performs a turning operation, the smaller the turning radius of the vehicle body, the lower the vehicle body speed during the turning operation. This makes it possible to suppress an increase in the speed of the user when the transport vehicle performs a turning operation. It is possible to suppress the user from being swung around when the transport vehicle performs a turning operation. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a perspective view of a transporter 2 according to the embodiment. [Diagram 2] FIG. 2 is a block diagram of a transporter 2 according to an embodiment. [Diagram 3] 10 is a flowchart of a turning operation process performed by a control unit 52 of the transporter 2 according to the embodiment. [Figure 4] 10 is a diagram showing a schematic diagram of a relationship between a vehicle body speed Vb and a user speed Vu when a transporter 2 according to an embodiment performs a turning operation. FIG. [Diagram 5] 13 is a graph showing an example of the relationship between the curvature of a turning motion of the transporter 2, the vehicle body speed, and the user speed. [Figure 6] 13 is a graph showing another example of the relationship between the curvature of a turning motion, the vehicle body speed, and the user speed in the transporter 2. [Figure 7] 4 is a graph showing an example of the relationship between the steering angle, the target vehicle body speed and its approximation function in the transporter 2 according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Representative and non-limiting examples of the present invention will now be described in detail with reference to the drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing preferred examples of the present invention, and is not intended to limit the scope of the present invention. Additionally, additional features and inventions disclosed below may be used separately or in conjunction with other features and inventions to provide further improved transport vehicles, methods of making and using the same.

[0009] Furthermore, the combinations of features and steps disclosed in the following detailed description are not essential to the practice of the invention in its broadest sense, but are specifically described only to illustrate representative embodiments of the invention. Furthermore, the various features of the representative embodiments described above and below, and the various features of those described in the independent and dependent claims, do not have to be combined in the exact embodiments described herein, or in the exact order listed, to provide additional and useful embodiments of the invention.

[0010] All features described in the specification and / or claims are intended to be disclosed individually and independently of one another as limitations to the original disclosure and claimed particulars, apart from any configuration of features described in the examples and / or claims. Furthermore, all numerical ranges and group or aggregate descriptions are intended to disclose their intermediate configurations as limitations to the original disclosure and claimed particulars.

[0011] In one or more embodiments, the transporter may further include a steering mechanism for steering at least one of the wheels as a steering wheel.

[0012] In a transport vehicle having a steering mechanism, a turning operation may be performed without reducing the vehicle body speed so much that the user is likely to be swung around when the transport vehicle turns. According to the above configuration, it is possible to prevent the user from being swung around when the transport vehicle having a steering mechanism turns.

[0013] In one or more embodiments, the handle may be supported on the vehicle body so as to be rotatable about a rotation axis and may be configured to be rotated by the user. The transporter may further include a handle angle sensor that detects a rotation angle of the handle about the rotation axis as a handle angle. The control unit may set a target steering angle of the steered wheels during the turning operation based on the handle angle. The control unit may set the target vehicle body speed during the turning operation based on the handle angle.

[0014] When the transport vehicle performs a turning operation in response to a user's turning operation of the steering wheel, the larger the steering wheel angle, the smaller the turning radius of the vehicle body, and the smaller the steering wheel angle, the larger the turning radius of the vehicle body. According to the above-mentioned simple configuration, when the turning radius of the vehicle body is small, the target vehicle body speed during the turning operation can be set to be smaller than when the turning radius of the vehicle body is large.

[0015] In one or more embodiments, the control unit may calculate the target vehicle speed as a linear function of the steering wheel angle.

[0016] According to the above configuration, the processing load on the control unit can be reduced.

[0017] In one or more embodiments, the prime mover may include a plurality of motors, one corresponding to each of the wheels.

[0018] According to the above configuration, the speed of the vehicle body can be easily adjusted when the transporter performs a turning operation.

[0019] (Example) The transporter 2 shown in FIG. 1 includes a vehicle body 4, a loading platform 6, a handlebar 8, a right front wheel 10, a left front wheel 12, a right rear wheel 14, and a left rear wheel 16. The loading platform 6, the handlebar 8, the right front wheel 10, the left front wheel 12, the right rear wheel 14, and the left rear wheel 16 are all supported by the vehicle body 4. The transporter 2 transports luggage loaded on the loading platform 6. The transporter 2 includes a wireless interface (I / F) 18 (see FIG. 2) mounted on the vehicle body 4. The transporter 2 can operate in any of a manual mode, an automatic mode, and a parking mode. In the manual mode, the transporter 2 moves forward or backward in response to an operation by a user standing behind the vehicle body 4 and holding the handlebar 8 with both hands. In the automatic mode, the transporter 2 performs a following driving mode in which it moves by tracking a beacon (not shown) carried by a user standing in front of the vehicle body 4, or a remote control driving mode in which it moves according to instructions from a remote control (not shown) operated by the user. In this case, the transporter 2 receives radio waves from the beacon or remote control via the wireless I / F 18. In the parking mode, the transporter 2 continues to stop on the spot without accepting commands from the handle 8 or commands from the beacon or remote control.

[0020] The transporter 2 includes a battery attachment section 20 provided on the vehicle body 4. A battery pack 22 (see FIG. 2) can be attached and detached to the battery attachment section 20. The battery pack 22 includes secondary battery cells (not shown), such as lithium ion battery cells, and can be recharged using a charger (not shown). The transporter 2 operates using power supplied from the battery pack 22 attached to the battery attachment section 20.

[0021] 2, the transporter 2 is equipped with a right front wheel motor 24 that drives the right front wheel 10, a left front wheel motor 26 that drives the left front wheel 12, a right rear wheel motor 28 that drives the right rear wheel 14, and a left rear wheel motor 30 that drives the left rear wheel 16. The right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, and the left rear wheel motor 30 are, for example, brushless motors. The right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, and the left rear wheel motor 30 are supported by the vehicle body 4.

[0022] As shown in FIG. 1, the handle 8 is rotatable around a rotation axis extending in the vertical direction relative to the vehicle body 4. A user can rotate the handle 8 while holding the handle 8 with both hands. As shown in FIG. 2, the transporter 2 is equipped with a handle angle sensor 32 that detects the rotation angle of the handle 8 as a handle angle, a steering mechanism 34 that steers the right front wheel 10 and the left front wheel 12 as steering wheels, and a steering motor 36 that drives the steering mechanism 34. The steering motor 36 is, for example, a brushless motor. The handle angle sensor 32, the steering mechanism 34, and the steering motor 36 are supported by the vehicle body 4.

[0023] As shown in FIG. 1, the handle 8 is provided with a switch box 38. As shown in FIG. 2, the switch box 38 is provided with a main power switch 40, a mode change switch 42, a trigger switch 44, a travel direction change switch 46, and a speed change switch 48. The main power switch 40 can switch the main power of the transporter 2 on / off. The mode change switch 42 can switch the operation mode of the transporter 2 among a manual mode, an automatic mode, and a parking mode. In the manual mode, the trigger switch 44 can switch on / off the forward and reverse of the transporter 2 and adjust the travel speed of the transporter 2. In the manual mode, the travel direction change switch 46 can switch the travel direction of the transporter 2. In the manual mode, the speed change switch 48 can switch the travel speed of the transporter 2. A user can operate a main power switch 40, a mode change switch 42, a trigger switch 44, a traveling direction change switch 46, and a speed change switch 48 while holding the handle 8 with both hands.

[0024] The transporter 2 includes a control power circuit 50 and a control unit 52. The control power circuit 50 allows the supply of power from the battery pack 22 when the main power switch 40 is turned on, and prohibits the supply of power from the battery pack 22 when the main power switch 40 is turned off. The control unit 52 controls the operation of the transporter 2. The control unit 52 controls the operation of the right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, the left rear wheel motor 30, and the steering motor 36 via motor drivers 54, 56, 58, 60, 62. Brake circuits 64, 66, 68, 70 are connected to the motor drivers 54, 56, 58, 60 in correspondence with the right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, and the left rear wheel motor 30. The control unit 52 can apply a large braking force to the right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, and the left rear wheel motor 30 by passing a large current through the brake circuits 64, 66, 68, and 70 while the right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, and the left rear wheel motor 30 are rotating. The control power supply circuit 50, the control unit 52, the motor drivers 54, 56, 58, 60, 62, and the brake circuits 64, 66, 68, and 70 are supported by the vehicle body 4.

[0025] (Turning operation processing) When the main power supply of the transporter 2 is on and the manual mode is selected, the control unit 52 executes the turning operation process shown in FIG.

[0026] In S2, the control unit 52 obtains the steering angle of the steering wheel 8 using the steering wheel angle sensor 32.

[0027] In S4, the control unit 52 determines target steering angles for the right front wheel 10 and the left front wheel 12 based on the steering wheel angle acquired in S2.

[0028] In S6, the control unit 52 determines a target vehicle body speed in the turning operation based on the steering angle acquired in S2.

[0029] In S8, the control unit 52 controls the steering motor 36 to drive the steering mechanism 34 based on the target steering angle specified in S4, and controls the right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, and the left rear wheel motor 30 to drive the right front wheel 10, the left front wheel 12, the right rear wheel 14, and the left rear wheel 16 in accordance with the target vehicle speed specified in S6. This realizes a turning operation of the transporter 2 so that the steering angles of the right front wheel 10 and the left front wheel 12 become the target steering angles specified in S4, and the speed of the vehicle body 4 becomes the target vehicle speed specified in S6. After S8, the process returns to S2.

[0030] (Control of vehicle speed during turning) FIG. 4 illustrates the relationship between the vehicle body speed Vb, which is the speed of the vehicle body 4, and the user speed Vu, which is the speed of the user U, when the transporter 2 is turning. In the example shown in FIG. 4, the user U turns the handlebars 8 clockwise when viewed from above, and the transporter 2 turns clockwise about the turning center Cr. In this case, the turning radius Ru of the user U is larger than the turning radius Rb of the vehicle body 4, so that the user speed Vu during the turning operation is larger than the vehicle body speed Vb during the turning operation. Specifically, the relationship Vu=Vb×Ru / Rb holds. As is clear from FIG. 4, the smaller the turning radius Rb of the vehicle body 4, the larger the value of Ru / Rb becomes, and the larger the turning radius Rb of the vehicle body 4, the smaller the value of Ru / Rb becomes, approaching 1.

[0031] FIG. 5 shows an example of the relationship between the curvature of the turning motion of the transporter 2 (the inverse of the turning radius Rb of the vehicle body 4), the vehicle body speed Vb, and the user speed Vu. In the example shown in FIG. 5, the vehicle body speed Vb is constant regardless of the curvature of the turning motion. In this case, if the curvature of the turning motion is small (i.e., if the turning radius Rb is large), the user speed Vu will be close to the vehicle body speed Vb, but if the curvature of the turning motion is large (i.e., if the turning radius Rb is small), the user speed Vu will be larger than the vehicle body speed Vb. Therefore, if the transporter 2 turns with a large curvature (i.e., with a small turning radius Rb), the user who is holding the handlebars 8 and walking behind the vehicle body 4 will be swung around.

[0032] Fig. 6 shows another example of the relationship between the curvature of the turning motion of the transporter 2, the vehicle body speed Vb, and the user speed Vu. In the example shown in Fig. 6, the vehicle body speed Vb is made smaller as the curvature of the turning motion increases (i.e., as the turning radius Rb decreases). In this case, the user speed Vu can be made constant regardless of the curvature of the turning motion. Therefore, even if the transporter 2 turns with a large curvature (i.e., with a small turning radius Rb), the user who is holding the handlebars 8 and walking behind the vehicle body 4 will not be swung around.

[0033] In the transport vehicle 2 of this embodiment, the larger the handle angle of the handle 8, the larger the steering angle of the steering mechanism 34, and the larger the curvature of the turning motion of the transport vehicle 2. Conversely, the smaller the handle angle of the handle 8, the smaller the steering angle of the steering mechanism 34, and the smaller the curvature of the turning motion of the transport vehicle 2. For this reason, even if the horizontal axis of the graphs in Figures 5 and 6 is replaced with the handle angle or steering angle, the same relationship holds between the vehicle speed Vb and the user speed Vu.

[0034] As shown in FIG. 7, the control unit 52 of this embodiment calculates the target vehicle body speed Vb as a function of the handle angle in order to keep the user speed Vu constant during a turning operation (see S6 in FIG. 3). FIG. 7 illustrates the relationship between the handle angle and the target vehicle body speed Vb for each of the cases where the travel speed of the transport vehicle 2 is low, medium, and high, but the same relationship holds for any speed according to the operation amount of the trigger switch 44. In the example shown in FIG. 7, the smaller the handle angle (i.e., the smaller the steering angle / the smaller the curvature of the turning operation / the larger the turning radius of the vehicle body 4), the larger the target vehicle body speed Vb in the turning operation is set to. Conversely, the larger the handle angle (i.e., the larger the steering angle / the larger the curvature of the turning operation / the smaller the turning radius of the vehicle body 4), the smaller the target vehicle body speed Vb in the turning operation is set to. By providing the target vehicle body speed Vb in this way, it is possible to prevent a user who is walking behind the vehicle body 4 while holding the handle 8 from being swung around during a turning operation of the transport vehicle 2. In addition, in S6 of FIG. 3, the control unit 52 may calculate the target vehicle speed Vb as a function of the steering angle, instead of calculating the target vehicle speed Vb as a function of the steering angle, may calculate the target vehicle speed Vb as a function of the curvature of the turning motion, or may calculate the target vehicle speed Vb as a function of the turning radius of the vehicle body 4.

[0035] As shown in FIG. 7, the target vehicle speed Vb for keeping the user speed Vu constant can be approximately calculated using a linear function of the handle angle (or a linear function of the steering angle, or a linear function of the curvature of the turning operation). For this reason, in the transporter 2 of this embodiment, the control unit 52 calculates the target vehicle speed Vb using a linear function of the handle angle. For example, the target vehicle speed Vb is calculated as Vb=Vb0×(1−a×θ / θmax). Here, Vb0 is the vehicle speed when traveling straight, θ is the handle angle, θ is the maximum handle angle (constant), and a is a positive constant. Such a configuration can reduce the processing load of the control unit 52.

[0036] In the above, the control of the vehicle speed during a turning operation performed by the control unit 52 when the transporter 2 moves forward has been described, but the control unit 52 may also perform a similar control when the transporter 2 moves backward.

[0037] (Modification) In the above embodiments, the right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, and the left rear wheel motor 30 may be in-wheel motors (not shown) incorporated into the right front wheel 10, the left front wheel 12, the right rear wheel 14, and the left rear wheel 16.

[0038] In the above embodiment, the right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, the left rear wheel motor 30, and the steering motor 36 may be brushed DC motors, AC motors, or other types of motors.

[0039] In the above embodiment, instead of the steering motor 36, the steering mechanism 34 may be driven by another type of actuator.

[0040] In the above embodiment, instead of the right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, and the left rear wheel motor 30, the right front wheel 10, the left front wheel 12, the right rear wheel 14, and / or the left rear wheel 16 may be driven by an internal combustion engine.

[0041] In the above embodiment, instead of using the battery pack 22, a configuration may be used in which power is supplied to the transporter 2 from a power source arranged outside the transporter 2 via a power cord.

[0042] As described above, in one or more embodiments, the transporter 2 includes the vehicle body 4, the right front wheel 10, the left front wheel 12, the right rear wheel 14, and the left rear wheel 16 (examples of wheels) supported by the vehicle body 4 and in contact with the ground, the right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, and the left rear wheel motor 30 (examples of prime movers) that drive the right front wheel 10, the left front wheel 12, the right rear wheel 14, and the left rear wheel 16, the handle 8 held by a user walking behind the vehicle body 4, and the control unit 52 that controls the operation of the right front wheel motor 24, the left front wheel motor 26, the right rear wheel motor 28, and the left rear wheel motor 30. When the transporter 2 performs a turning operation, the control unit 52 sets a target vehicle speed during the turning operation to be smaller when the turning radius of the vehicle body 4 is small compared to when the turning radius of the vehicle body 4 is large.

[0043] According to the above configuration, when the transporter 2 performs a turning operation, the smaller the turning radius of the vehicle body 4, the more the speed of the vehicle body 4 during the turning operation can be reduced. This makes it possible to suppress an increase in the speed of the user when the transporter 2 performs a turning operation. It is possible to suppress the user from being swung around when the transporter 2 performs a turning operation.

[0044] In one or more embodiments, the transporter 2 further includes a steering mechanism 34 that steers the right front wheel 10 and the left front wheel 12 as steered wheels.

[0045] In the transporter 2 having the steering mechanism 34, a turning operation may be performed without significantly reducing the speed of the vehicle body 4, so that the user is likely to be swung around when the transporter 2 performs a turning operation. According to the above configuration, it is possible to prevent the user from being swung around when the transporter 2 having the steering mechanism 34 performs a turning operation.

[0046] In one or more embodiments, the handle 8 is supported on the vehicle body 4 so as to be rotatable about a rotation axis, and is configured to be rotated by a user. The transporter 2 further includes a handle angle sensor 32 that detects a rotation angle of the handle 8 about the rotation axis as a handle angle. The control unit 52 sets a target steering angle of the steered wheels during a turning operation based on the handle angle. The control unit 52 sets a target vehicle speed during a turning operation based on the handle angle.

[0047] When the transporter 2 performs a turning operation in response to a user's turning operation of the handlebars 8, the larger the handlebar angle, the smaller the turning radius of the vehicle body 4, and the smaller the handlebar angle, the larger the turning radius of the vehicle body 4. According to the above-mentioned simple configuration, the target vehicle body speed during a turning operation can be set to a smaller value when the turning radius of the vehicle body 4 is small, compared to when the turning radius of the vehicle body 4 is large.

[0048] In one or more embodiments, the control unit 52 calculates the target vehicle speed as a linear function of the steering wheel angle.

[0049] According to the above configuration, the processing load on the control unit 52 can be reduced.

[0050] In one or more embodiments, a right front wheel motor 24, a left front wheel motor 26, a right rear wheel motor 28, and a left rear wheel motor 30 are provided corresponding to the right front wheel 10, the left front wheel 12, the right rear wheel 14, and the left rear wheel 16, respectively.

[0051] According to the above configuration, the speed of the vehicle body 4 can be easily adjusted when the transporter 2 performs a turning operation. [Explanation of symbols]

[0052] 2: Transport vehicle 4: Body 6: Cargo platform 8: Handle 10: Right front wheel 12:Left front wheel 14: Right rear wheel 16: Left rear wheel 18: Wireless I / F 20: Battery mounting section 22: Battery pack 24: Right front wheel motor 26: Left front wheel motor 28: Right rear wheel motor 30: Left rear wheel motor 32: Steering wheel angle sensor 34: Steering mechanism 36: Steering motor 38: Switch box 40: Main power switch 42: Mode switch 44: Trigger switch 46: Direction change switch 48: Speed ​​change switch 50: Control power circuit 52: Control unit 54: Motor driver 56: Motor driver 58: Motor driver 60: Motor driver 62: Motor driver 64: Brake circuit 66: Brake circuit 68: Brake circuit 70: Brake circuit

Claims

1. A transport vehicle, The car body and A wheel supported by the vehicle body and in contact with the ground; A prime mover that drives the wheels; A handle that is gripped by a user walking behind the vehicle body; A control unit for controlling the operation of the prime mover is provided. The control unit sets the target vehicle speed during a turning operation to be smaller when the turning radius of the vehicle body is small compared to when the turning radius of the vehicle body is large when the vehicle performs a turning operation.

2. The transporter of claim 1 , further comprising a steering mechanism for steering at least one of said wheels as a steering wheel.

3. The handle is supported on the vehicle body so as to be rotatable around a rotation axis, and is configured to be rotated by the user, The steering wheel angle sensor detects a rotation angle of the steering wheel around the rotation axis as a steering wheel angle. The control unit sets a target steering angle of the steered wheels during the turning operation based on the steering wheel angle, The transporter according to claim 2 , wherein the control unit sets the target vehicle speed during the turning operation based on the handle angle.

4. 4. The vehicle of claim 3, wherein the control unit calculates the target vehicle speed as a linear function of the steering angle.

5. 5. The transporter according to claim 1, wherein the prime mover comprises a plurality of motors provided corresponding to the respective wheels.

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