vehicle

Abstract

To provide a vehicle that includes a vehicle body frame, a drive unit that allows the vehicle body frame to travel under inverted pendulum control, and a seat elastically connected to the vehicle body frame, and that can accurately obtain a tilt angle of a floor surface.SOLUTION: A vehicle 1 includes a vehicle body frame 2, a vehicle body tilt sensor 7 that is incorporated in the vehicle body frame and detects a tilt angle of the vehicle body frame, a drive unit 3 that is coupled to the vehicle body frame and allows the vehicle body frame to move on a floor surface under inverted pendulum control on the basis of the tilt angle detected by the vehicle body tilt sensor, a seat body 15 on which a user is seated, and legs 24 and 27 extending downward. The legs can ascend or descend between a low position at which the legs come into contact with the floor surface and a high position at which the legs recede from the floor surface. The vehicle further includes a seat 4 elastically coupled to the vehicle body frame. A seat tilt sensor 28 that detects a tilt angle of the seat is incorporated.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a moving body that can move in response to the movement of the center of gravity of a passenger. [Background technology]

[0002] A moving body that can move in response to the movement of the center of gravity of a passenger is known (for example, Patent Document 1). The moving body has a traveling motion unit that can move in all directions on a floor surface, a base body assembled to the traveling motion unit, a passenger riding unit attached to the base body via a connecting mechanism, and a plurality of training wheels connected to the passenger riding unit.

[0003] The connecting mechanism has an elastic structure that allows the occupant riding section to elastically swing relative to the base body, and a lifting mechanism that allows the occupant riding section to rise and fall relative to the base body. When the training wheels are raised above the floor surface by the lifting mechanism from a state in which the training wheels are in contact with the ground, movement control (inverted pendulum control) of the traveling motion section is performed based on the measurement values ​​of the tilt sensors provided on the base body so that the overall center of gravity of the mobile body is balanced in a manner similar to the mass point of an inverted pendulum. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 244444 Summary of the Invention [Problem to be solved by the invention]

[0005] In the moving body of Patent Document 1, when the training wheels are in a state where they are in contact with the ground, the traveling motion unit does not perform inverted pendulum control, and the occupant riding unit and the base body are connected by an elastic structure. Therefore, even when the training wheels are in a state where they are in contact with the ground, the tilt angle of the base body does not match the tilt angle of the floor, making it difficult to obtain the tilt angle of the floor.

[0006] In view of the above background, the present invention aims to accurately obtain the inclination angle of the floor of a vehicle having a body frame, a drive unit that drives the body frame using inverted pendulum control, and a seat elastically connected to the body frame, thereby contributing to the development of sustainable transportation systems. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, one aspect of the present invention is a vehicle (1) comprising a body frame (2), a body inclination sensor (7) provided on the body frame and detecting the inclination angle of the body frame, a drive unit (3) connected to the body frame and configured to move the body frame along a floor surface by inverted pendulum control based on the inclination angle detected by the body inclination sensor, a seat body (15) on which a user sits, and a seat (4) having legs (24, 27) extending downward, which can be raised and lowered between a low position where the legs contact the floor surface and a high position where the legs are separated from the floor surface and which is elastically connected to the body frame, and a seat inclination sensor (28) provided on the seat to detect the inclination angle of the seat.

[0008] According to this aspect, when the seat is in the low position, the legs of the seat come into contact with the floor surface, so that the inclination angle of the floor surface can be obtained by the seat inclination sensor.

[0009] In order to solve the above problem, one aspect of the present invention comprises a lifting device (5) that raises and lowers the seat relative to the body frame, and a control device (6) that controls the operation of the lifting device, and the control device determines whether or not to operate the lifting device based on the detection results of the seat inclination sensor.

[0010] According to this aspect, when the seat is in the low position, it is determined whether the seat can be raised by the lifting device based on the inclination angle acquired by the seat inclination sensor, thereby enabling a more accurate determination of whether the seat can be raised based on the inclination angle of the floor surface.

[0011] In the above aspect, preferably, the control device determines that the seat tilt sensor and the vehicle body tilt sensor are normal when the difference between the seat tilt angle acquired by the seat tilt sensor and the vehicle body frame tilt angle acquired by the vehicle body tilt sensor is equal to or smaller than a predetermined threshold, and determines that either the seat tilt sensor or the vehicle body tilt sensor is faulty when the difference between the seat tilt angle acquired by the seat tilt sensor and the vehicle body frame tilt angle acquired by the vehicle body tilt sensor is greater than the predetermined threshold.

[0012] According to this aspect, a failure in either the vehicle body tilt sensor or the seat tilt sensor can be determined with a simple configuration.

[0013] In the above aspect, preferably, two of the drive units are provided on the body frame, each of the drive units being disk-shaped and arranged coaxially, and supported on the body frame so as to be rotatable about an axis (Y), and the body tilt sensor is located on a virtual line (X) that passes through the center of the two drive units and is perpendicular to the axis.

[0014] According to this aspect, the tilt angle of the body frame can be obtained appropriately.

[0015] In the above aspect, the seat tilt sensor is preferably provided at a position separated from the virtual line.

[0016] According to this aspect, it is possible to improve the accuracy of detecting the inclination angle by the seat inclination sensor.

[0017] In the above aspect, the seat tilt sensor is preferably provided on the seat body.

[0018] According to this aspect, even when movable legs are used, the inclination angle of the floor surface can be appropriately obtained. [Effects of the Invention]

[0019] According to the above configuration, the inclination angle of the floor surface can be accurately obtained in a vehicle having a body frame, a drive unit that moves the body frame using inverted pendulum control, and a seat elastically connected to the body frame. [Brief explanation of the drawings]

[0020] [Figure 1] Left side view of the vehicle with the seat in the low park position [Figure 2] Left side view of vehicle with seat in high position [Figure 3] Cross section of the drive unit [Figure 4] A perspective view of a seat frame assembly [Figure 5] Left side view of the vehicle with the seat in the low drive position [Figure 6] Flowchart of determination process [Figure 7] Schematic diagram showing the vehicle on a ramp that slopes forward and backward, with the seat in a low-stop position [Figure 8] Schematic diagram showing the state of a vehicle on a slope that slopes left and right and with the seat in a low-stop position DETAILED DESCRIPTION OF THE INVENTION

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle according to the present invention will now be described with reference to the accompanying drawings. In this embodiment, the vehicle is configured as an inverted pendulum vehicle.

[0022] As shown in Figure 1, vehicle 1 is a one-person vehicle that can move in all directions on the floor surface according to the movement of the center of gravity of the seated user. Below, the structure of vehicle 1 will be described by defining front-to-back, left-to-right, and up-to-down directions based on the orientation of the user seated in vehicle 1. However, the descriptions of front-to-back, left-to-right, and up-to-down directions are for the convenience of explanation, and the present invention is not limited by these directional descriptions.

[0023] As shown in Figures 1 and 2, the vehicle 1 has a body frame 2, at least one drive unit 3 mounted on the body frame 2 and movable on the floor, a seat 4 positioned above the body frame 2 and supporting the user's buttocks, a lifting device 5 mounted between the body frame 2 and the seat 4, and a control device 6 that controls the drive unit 3 and the lifting device 5.

[0024] The body frame 2 includes a lower frame 2A extending in the left-right direction and an upper frame 2B extending upward from approximately the center of the lower frame 2A. The lower end of the upper frame 2B is connected to approximately the center of the lower frame 2A in the left-right direction. The lower end of the upper frame 2B is pivotally supported relative to the lower frame 2A so as to be swingable about an axis Z extending in the front-rear direction (see FIG. 8). A body inclination sensor 7 is provided on the upper part of the upper frame 2B.

[0025] The body tilt sensor 7 detects the tilt angle of the body frame 2 with respect to the horizontal plane (hereinafter referred to as the body tilt angle). The body tilt sensor 7 is configured with a known device that detects acceleration and angular velocity in three axial directions and sequentially measures (estimates) the body tilt angle by performing strap-down calculation processing. However, the body tilt sensor 7 is not limited to this embodiment, and may be, for example, a sensor that detects the body tilt angle based on changes in the direction of gravitational acceleration with respect to the body frame 2. In that case, the body tilt sensor 7 may be configured with a known device based on MEMS technology.

[0026] In this embodiment, the body tilt angle includes two angles: a roll angle of the body frame 2 and a pitch angle of the body frame 2. Each angle is defined with a reference angle (0 degrees) set to when the vehicle 1 is stationary on a horizontal plane and placed without a user seated on it.

[0027] The vehicle 1 is equipped with a pair of left and right drive units 3 (see Figure 8). The drive units 3 are provided on the left and right sides of the body frame 2, respectively. The drive units 3 are disk-shaped in side view. The drive units 3 are arranged coaxially around an axis Y extending in the left-right direction. The drive units 3 are arranged symmetrically on the left and right sides of the upper frame 2B, and are each supported by the lower frame 2A so as to be rotatable about the axis Y.

[0028] 1, the vehicle body tilt sensor 7 is located on an imaginary line X that passes through the center of the two drive units 3 and intersects with the axis Y. When the vehicle 1 is located on a horizontal plane, the imaginary line X is perpendicular to the axis Y and the axis Z and extends vertically.

[0029] In this embodiment, each drive unit 3 is a friction drive device. As shown in FIG. 3, each drive unit 3 includes a pair of drive discs 10 rotatably supported on the vehicle body frame 2, a plurality of drive rollers 11 rotatably supported on each of the drive discs 10, an annular drive wheel 8 disposed between the left and right drive discs 10 and in contact with the drive rollers 11, and a pair of actuators 12 for independently rotating each of the pair of drive discs 10. The pair of drive discs 10 are disposed coaxially with each other, with their rotation axes extending in the left-right direction. As shown in FIG. 1, each actuator 12 includes an electric motor 12A and a transmission mechanism 12B that transmits the rotational force of the electric motor 12A to the corresponding drive disc 10. The transmission mechanism 12B may be, for example, a belt transmission mechanism. The electric motor 12A may be disposed above the drive discs 10.

[0030] The drive wheel 8 is annular and is disposed coaxially with the drive disks 10 between a pair of drive disks 10. As shown in FIG. 1, the drive wheel 8 is in contact with a plurality of drive rollers 11 and is rotatable around a central axis and an annular axis. The drive wheel 8 has, for example, an annular core body 13 and a plurality of driven rollers 14 rotatably supported on the core body 13. Each driven roller 14 is supported on the core body 13 so as to be rotatable around the axis of the annular core body 13. Each driven roller 14 receives a load from the drive disks 10 and rotates relative to the core body 13.

[0031] When the pair of drive discs 10 rotate in the same direction at the same rotational speed, the drive wheels 8 rotate in the same direction at the same rotational speed as the drive discs 10. When a difference occurs in the rotational direction or rotational speed of the pair of drive discs 10, the driven rollers 14 of the drive wheels 8 rotate relative to the core body 13. This allows the drive unit 3 to generate propulsive force in the left and right directions relative to the floor surface.

[0032] As shown in Fig. 1, the seat 4 has a seat body 15 on which a user sits, a plurality of first legs 24, and a plurality of second legs 27. The seat body 15 has a seat frame 18 and a pad 19 supported on the upper part of the seat frame 18. The first legs 24 and the second legs 27 each constitute a leg portion extending downward from the seat body 15. In this embodiment, the seat 4 has four first legs 24 and four second legs 27.

[0033] As shown in Fig. 4, the seat frame 18 has a rectangular frame shape when viewed from above. The seat frame 18 includes a pair of left and right side frames 18A extending in the front-to-rear direction, a front frame 18B connecting the front ends of the side frames 18A, and a rear frame 18C connecting the rear ends of the side frames 18A. Support pieces 21 extending inward are provided at each of the four corners of the seat frame 18.

[0034] The seat body 15 is provided with a seat inclination sensor 28. Unlike the vehicle body inclination sensor 7, the seat inclination sensor 28 is provided at a position away from the imaginary line X. In this embodiment, the seat inclination sensor 28 is provided at one of the four corners of the seat frame 18. The seat inclination sensor 28 may be provided at any of the four corners, and for example, may be provided on a support piece 21 located at either the left or right corner located on the rear side of the four corners of the seat frame 18.

[0035] The seat tilt sensor 28 detects the tilt angle of the seat frame 18 (hereinafter referred to as the seat tilt angle). Like the vehicle body tilt sensor 7, the seat tilt sensor 28 is configured with a known device that detects acceleration and angular velocity in three axial directions and sequentially measures (estimates) the seat tilt angle by performing strap-down calculation processing. However, the seat tilt sensor 28 is not limited to this embodiment and may be a sensor that detects the seat tilt angle based on, for example, a change in the direction of gravitational acceleration relative to the vehicle body frame 2. In that case, the seat tilt sensor 28 may be configured with a known device based on MEMS technology. Alternatively, the seat tilt sensor 28 may be a sensor that detects only a specific angle, and its detection method is not limited to the strap-down method or a method based on a change in the direction of gravitational acceleration.

[0036] In this embodiment, the seat tilt angle includes two angles: the roll angle of the seat frame 18 and the pitch angle of the seat frame 18. Each angle is defined with the reference angle (0 degrees) being when the vehicle 1 is stationary on a horizontal plane and placed without a user seated on it.

[0037] As shown in Fig. 1, pad 19 is made of a cushioning material and is disposed on the upper side of seat frame 18. Pad 19 is disposed on the upper side of support piece 21 and is supported by seat frame 18 via support piece 21. The upper surface of pad 19 forms a seating surface that supports the user's buttocks.

[0038] 4, the first legs 24 and the second legs 27 are respectively connected to the seat frame 18 via leg support parts 29 provided at the four corners of the seat frame 18. Each leg support part 29 is connected to one of the first legs 24 and the second legs 27.

[0039] The upper end of the first leg 24 is rotatably connected to the leg support portion 29. The first leg 24 is rotatable between a stored position in which it is disposed close to the body frame 2 and an extended position which is further to the side from the body frame 2 than the stored position. A biasing member (not shown) is provided between the body frame 2 and the first leg 24 to bias the first leg 24 from the extended position toward the stored position.

[0040] Each of the first legs 24 includes a first upper leg portion 24B, a first lower leg portion 24C rotatably connected to the first upper leg portion 24B via a joint 24A, and a roller 23 attached to the lower end of the first lower leg portion 24C. The roller 23 is generally cylindrical. The roller 23 is disposed with its central axis generally horizontal and is connected to the lower end of the first lower leg portion 24C so that its central axis is rotatable. The first lower leg portion 24C preferably supports the roller 23 so that its axis is rotatable about a vertical axis. When each of the rollers 23 is in contact with the floor surface, the seat 4 is movable along the floor surface.

[0041] The upper end of second leg 27 is fixed to leg support 29. Second leg 27 is configured to be extendable and retractable in the vertical direction. Second leg 27 includes second leg upper portion 27A, second leg lower portion 27B, and abutment member 26.

[0042] The second leg upper portion 27A is fixed at its upper end to the leg support portion 29 and extends downward. The second leg lower portion 27B protrudes downward from the second leg upper portion 27A and is supported so as to be movable in the up and down direction. An abutting member 26 is provided at the lower end of the second leg lower portion 27B. The abutting member 26 preferably has a higher flexibility than the second leg lower portion 27B. The abutting member 26 also preferably has a higher coefficient of friction than the second leg lower portion 27B. The abutting member 26 may be formed of, for example, rubber or elastomer. When the abutting member 26 comes into contact with the ground, the vehicle 1, which is grounded via the rollers 23, can be maintained in a stopped state.

[0043] The contact members 26 come into contact with the floor surface, thereby applying a frictional force to the vehicle 1 that is moving due to the rotation of the rollers 23, thereby maintaining it in a stopped state.

[0044] A biasing member is interposed between second leg upper portion 27A and second leg lower portion 27B to bias second leg lower portion 27B downward relative to second leg upper portion 27A. The biasing member may include a compression coil spring. In this embodiment, the biasing member is disposed inside second leg lower portion 27B and abuts against the lower end of second leg upper portion 27A. This allows second leg 27 to expand and contract in response to an upward load applied to the lower end.

[0045] The lifting device 5 is a device that raises and lowers the seat 4. As shown in Figs. 1 and 2, the lifting device 5 is coupled to the body frame 2 and the seat frame 18. The lifting device 5 extends and contracts in the vertical direction, thereby displacing the seat frame 18 up and down relative to the body frame 2.

[0046] The lifting device 5 has a movable body 5A and a drive device 5B that is connected to the body frame 2 and moves the movable body 5A up and down relative to the body frame 2. The drive device 5B may have a ball screw mechanism and an electric motor that drives the ball screw mechanism.

[0047] An elastic member 31 is provided between the movable body 5A and the seat 4. The elastic member 31 has cushioning properties and deforms in response to an applied load. The elastic member 31 may be made of, for example, rubber. The elastic member 31 tilts the seat frame 18 relative to the movable body 5A in response to the load from the user, the inclination of the floor, etc. In this way, the lifting device 5 is directly connected to the body frame 2, and is connected to the seat frame 18 via the elastic member 31. As a result, the seat 4 is elastically connected to the body frame 2 and is capable of moving up and down. The seat 4 is capable of tilting relative to the body frame 2.

[0048] Operation panels 60B are provided on the left and right sides of the seat 4. The operation panel 60B is provided with a power switch 61A, a lift switch 61B, a movement direction switch 61C, and a driving mode changeover switch 61D. Each of the multiple switches is connected to the control device 6.

[0049] A pair of left and right levers 34 are provided on the seat frame 18. The levers 34 are located on the left and right outer sides of the operation panel 60B. When a user operates one of the left and right levers 34, as shown in FIG. 5, the second legs 27 retract upward and the contact members 26 move away from the floor. This state is called the low-position travel-enabled state. In the low-position travel-enabled state, the user can travel the vehicle 1 by operating the travel direction switch 61C. When the user returns the lever 34 to its initial position, the second legs 27 extend and the contact members 26 come into contact with the floor, preventing the vehicle 1 from moving.

[0050] The control device 6 is provided inside or at the rear of the body frame 2. The control device 6 is configured by a computer equipped with a central processing unit (CPU), memories such as RAM and ROM, and storage devices such as HDD and SSD. The control device 6 may be connected to an alarm device 62 that notifies the user. The alarm device 62 may be, for example, a speaker that notifies the user by voice. The alarm device 62 may be provided in any location as long as it is located in a position where it can notify the user, and may be provided inside the operation panel 60B, for example.

[0051] In addition, a control device 6, a lifting device 5, and a battery for operating the drive unit 3 may be supported at the rear of the body frame 2.

[0052] As shown in Figure 1, when the lever 34 is not operated and the vehicle 1 is stopped, each of the second legs 27 is extendable and retractable, so that the abutment members 26 are in contact with the floor surface. The abutment of the abutment members 26 keeps the vehicle 1 stationary and motionless. This state in which the abutment members 26 are in contact with the floor surface and the vehicle 1 is stopped is referred to as a low-position stopped state.

[0053] When the power switch 61A is turned on and the lever 34 is operated, as shown in FIG. 5, the second legs 27 retract upward and the contact members 26 move away from the floor. This causes both the rollers 23 and the drive unit 3 to come into contact with the floor. When the travel direction switch 61C is operated, the control device 6 controls the drive unit 3 in accordance with the operation to cause the vehicle 1 to travel. This state in which the rollers 23 and the drive unit 3 both remain in contact with the floor and the vehicle 1 travels on the floor is referred to as a low-position travelable state. However, while FIG. 5 shows the second legs 27 as being away from the floor, this is not limiting. For example, the second legs 27 may be slidably contacted with the floor via rollers (not shown) or the like.

[0054] When the power switch 61A and the lift switch 61B are turned on, the control device 6 determines whether a predetermined condition is met, thereby determining whether the seat 4 may be raised and setting a value corresponding to the flag. The predetermined condition is a condition required for raising the seat 4 and performing inverted pendulum control to propel the vehicle 1, such as ensuring that the floor is not too inclined. When the flag is subsequently set to a value indicating that the seat 4 may be raised, the control device 6 drives the lifting device 5 to raise the seat frame 18 relative to the body frame 2, as shown in FIG. 2, so that the rollers 23 and the abutment members 26 are lifted off the floor. At this time, only the drive wheels 8 of the left and right drive units 3 contact the ground, and the posture of the vehicle 1 is maintained by inverted pendulum control based on the tilt angle detected by the body tilt sensor 7. In this state, the control device 6 detects the displacement of the center of gravity of the vehicle 1 due to the user's weight shift and controls the drive units 3 to propel the vehicle 1. That is, the drive unit 3 moves the body frame 2 along the floor surface by inverted pendulum control based on the tilt angle of the body frame 2 detected by the body tilt sensor 7. In this way, the state in which the contact members 26 and rollers 23 are separated from the floor surface and only the left and right drive units 3 are in contact with the floor surface is called the high position.

[0055] Next, the details of the determination process performed by the control device 6 will be described with reference to FIG.

[0056] In the first step ST1 of the determination process, the control device 6 acquires the vehicle body inclination angle, which is the detection result, from the vehicle body inclination sensor 7, and acquires the seat inclination angle, which is the detection result, from the seat inclination sensor 28. Thereafter, the control device 6 calculates the difference (absolute difference) between the vehicle body inclination angle and the seat inclination angle, and determines whether the difference is equal to or smaller than a predetermined normal threshold value.

[0057] Specifically, when the difference between the roll angle of the vehicle body tilt angle and the roll angle of the seat tilt angle and the difference between the pitch angle of the vehicle body tilt angle and the pitch angle of the seat tilt angle are both equal to or less than the normal threshold, the control device 6 determines that the difference between the vehicle body tilt angle and the seat tilt angle is equal to or less than the normal threshold and executes step ST2. When at least one of the difference between the roll angle of the vehicle body tilt angle and the roll angle of the seat tilt angle and the difference between the pitch angle of the vehicle body tilt angle and the pitch angle of the seat tilt angle is greater than the normal threshold, the control device 6 executes step ST3.

[0058] In step ST2, the control device 6 determines whether the seat tilt angle is equal to or less than a predetermined increase threshold. Specifically, when the roll angle of the seat tilt angle is equal to or less than the increase threshold and the pitch angle of the seat tilt angle is equal to or less than the increase threshold, the control device 6 determines that the seat tilt angle is equal to or less than the predetermined increase threshold, and executes step ST4. When at least one of the roll angle of the seat tilt angle and the pitch angle of the seat tilt angle is greater than the increase threshold, the control device 6 executes step ST5.

[0059] In step ST3, the control device 6 determines that there is an abnormality in at least one of the vehicle body inclination sensor 7 and the seat inclination sensor 28, and sets a flag to a value indicating that the seat 4 cannot be raised due to an abnormality in the sensor. At this time, the control device 6 may output a notification from the alarm device 62 (speaker) that there is an abnormality in the inclination sensor. Once the flag setting and the output from the alarm device 62 are complete, the control device 6 ends the determination process.

[0060] In step ST4, the control device 6 sets a flag to a value indicating that the seat 4 may be raised. At this time, the control device 6 may output a notification from the notification device 62 (speaker) that the seat 4 may be raised. Once the flag setting and the output from the notification device 62 are complete, the control device 6 ends the determination process.

[0061] In step ST5, the control device 6 sets a flag to a value indicating that the inclination of the floor surface is too steep and therefore the lifting of the seat 4 is not permitted. At this time, the control device 6 may output a notification from the notification device 62 (speaker) that the inclination of the floor surface is too steep. Once the flag setting and the output from the notification device 62 are complete, the control device 6 ends the determination process.

[0062] Next, the effects of the vehicle 1 configured in this manner will be described.

[0063] The vehicle 1 includes a body frame 2 and a seat frame 18. When the vehicle 1 is stopped, the first leg 24 and the second leg 27 are in a state of being in contact with the ground. When the body frame 2 and the seat frame 18 are fixed and integrated and the first leg 24 and the second leg 27 are in contact with the ground, a load from the floor surface is transmitted to the first leg 24 and the second leg 27, and this load is transmitted to the body frame 2 via the seat frame 18, making it difficult to perform inverted pendulum control on the body frame 2.

[0064] Therefore, the inventors of the present application came up with the idea of ​​suppressing the transmission of load from the first leg 24 and the second leg 27 to the body frame 2 by elastically coupling the body frame 2 and the seat frame 18. By elastically coupling the body frame 2 to the seat frame 18 and connecting them in a displaceable manner, it is believed that inverted pendulum control of the body frame 2 becomes possible until the first leg 24 and the second leg 27 leave the floor surface.

[0065] However, the inventors of the present application have found that even when the body frame 2 and the seat frame 18 are elastically coupled, if the inclination angle of the floor surface is equal to or greater than a predetermined value, the range of deformation of the elastic member 31 is exceeded, making it difficult to raise the lower frame 2A of the body frame 2. Therefore, the inventors of the present application have attempted to install a sensor in the vehicle 1 to accurately detect the angle of the floor surface.

[0066] 7 and 8 are schematic diagrams showing the state of the body frame 2 and the seat 4 when the vehicle 1 is stopped on an inclined surface. As shown in FIGS. 7 and 8, when the vehicle 1 is stopped, the first leg 24 and the second leg 27 are in contact with the ground, and the seat 4 is on the ground. However, because the rotation of the drive unit 3 is not restricted, for example, gravity may cause the drive wheels 8 to rotate, causing the upper frame 2B to tilt from its upright position. Therefore, when the vehicle 1 is stopped, depending on the inclination angle of the floor, the inclination angle of the body frame 2 and the inclination angle of the seat frame 18 may not match.

[0067] When the seat 4 is in a low position, the second leg 27 (and the first leg 24) touches the ground, and the inclination angle detected by the seat inclination sensor 28 is the inclination angle of the floor surface. In this way, by providing the seat inclination sensor 28 in addition to the body inclination sensor 7 in the vehicle 1, the inclination angle of the floor surface can be detected more accurately when the vehicle 1 is stopped on an inclined surface.

[0068] Furthermore, in the determination process, when the control device 6 determines, based on the inclination angle acquired by the seat inclination sensor 28, that the inclination angle is equal to or less than the ascent threshold, the control device 6 sets the flag to a value indicating that ascent is possible, and the lifting device 5 raises the seat 4. In this way, whether or not the seat 4 can be raised is determined based on the value of the seat inclination sensor 28, rather than the value of the vehicle body inclination sensor 7, so that it is possible to determine whether or not the seat 4 can be raised based on the accurate inclination angle of the floor. This further enhances the safety of the vehicle 1 and can contribute to the development of a sustainable transportation system that takes the needs of vulnerable people, particularly the disabled and the elderly, into greater consideration.

[0069] The inventors of the present application have discovered that such displacement of the body frame 2 is limited by the deformation of the elastic member 31, and therefore the absolute value (magnitude) of the difference between the tilt angle of the body frame 2 and the tilt angle of the seat 4 is limited within a normal threshold value.

[0070] If the difference between the body inclination sensor 7 and the seat inclination sensor 28 is greater than the normal threshold (No in ST1), a flag is set to a value indicating that the inclination sensor is abnormal and that raising of the seat 4 is not permitted (ST3). In this way, with a simple configuration using two inclination sensors, the body inclination sensor 7 and the seat inclination sensor 28, it is possible to easily determine whether one of the two inclination sensors is abnormal. Furthermore, if either one of the inclination sensors is abnormal, raising of the seat 4 is prohibited, thereby improving the safety of the vehicle 1.

[0071] The body inclination sensor 7 is located on an imaginary line X that passes through the center of the two drive units 3. Based on the body inclination angle acquired by the body inclination sensor 7, the control device 6 performs inverted pendulum control of the drive units 3 so that the lower frame 2A of the body frame 2 is vertical.

[0072] The seat frame 18 is connected to the body frame 2 via an elastic member 31. Therefore, the tilt angle of the seat frame 18 does not match the tilt angle of the body frame 2. Therefore, by providing a body tilt sensor 7 for controlling the drive unit 3 on the body frame 2, the body frame 2 can be moved along the floor surface by inverted pendulum control. Furthermore, by providing the body tilt sensor 7 on an imaginary line X that passes through the center of the two drive units 3 and is perpendicular to the axis Y when the vehicle 1 is placed on a horizontal surface, stable inverted pendulum control by the two drive units 3 becomes possible.

[0073] When the seat inclination sensor 28 detects the seat inclination angle based on gravitational acceleration, the seat inclination sensor 28 may be provided at any position on the seat frame 18. When the seat inclination sensor 28 is of a type that successively measures (estimates) the seat inclination angle by, for example, detecting acceleration and angular velocity in three axial directions and performing strap-down arithmetic processing of the seat inclination angle, the seat inclination sensor 28 may be provided close to one of the four corners of the seat frame 18. This results in the seat inclination sensor 28 being provided at a position away from the imaginary line X. As a result, the magnitude of the detected axial acceleration and angular velocity becomes larger than when the seat inclination sensor 28 is provided on the imaginary line X. Therefore, when the seat inclination angle is successively measured (estimated) by using an acceleration sensor as the seat inclination sensor 28 and performing strap-down arithmetic processing of the seat inclination angle, the detection accuracy of the acquired seat inclination angle can be improved compared to when the seat inclination sensor 28 is provided on the imaginary line X.

[0074] If the seat inclination sensor 28 is provided with a movable first leg 24 or second leg 27, the seat inclination angle detected by the seat inclination sensor 28 may not reflect the inclination angle of the floor. In this embodiment, the seat inclination sensor 28 is provided on the seat frame 18, i.e., the seat body 15, and therefore the inclination angle of the floor can be appropriately obtained.

[0075] Although the description of the specific embodiment has been completed above, the present invention is not limited to the above embodiment and its modifications, and can be modified in a wide range of ways.

[0076] In the above embodiment, the control device 6 determines that the difference between the vehicle body tilt angle and the seat tilt angle is equal to or smaller than the normal threshold when the difference between the roll angle of the vehicle body tilt angle and the roll angle of the seat tilt angle and the difference between the pitch angle of the vehicle body tilt angle and the pitch angle of the seat tilt angle are both equal to or smaller than the normal threshold. However, this is not limiting. The control device 6 may also determine that both the vehicle body tilt sensor 7 and the seat tilt sensor 28 are normal when the difference between the roll angle of the vehicle body tilt angle and the roll angle of the seat tilt angle is equal to or smaller than a predetermined first normal threshold and the difference between the pitch angle of the vehicle body tilt angle and the pitch angle of the seat tilt angle is equal to or smaller than a predetermined second normal threshold. The first normal threshold and the second normal threshold may be different from each other. For example, the first normal threshold may be set to be smaller than the second normal threshold.

[0077] In the above embodiment, the control device 6 determines that the seat tilt angle is equal to or less than the predetermined rising threshold when the roll angle of the seat tilt angle is equal to or less than the rising threshold and the pitch angle of the seat tilt angle is equal to or less than the rising threshold, but this is not limited to this. The control device 6 may calculate the tilt angle of the seat 4 itself based on both the roll angle and the pitch angle, and determine that the seat tilt angle is equal to or less than the predetermined rising threshold when the calculated tilt angle of the seat 4 is equal to or less than the rising threshold. [Explanation of symbols]

[0078] 1: Vehicles 2: Body frame 2A: Lower frame 2B: Upper frame 3: Drive unit 4: Sheet 5: Lifting device 5A: Movable body 5B: Drive unit 6: Control device 7: Body tilt sensor 8: Drive wheel 10: Drive disk 11: Drive roller 12: Actuator 12A: Electric motor 12B: Transmission mechanism 13: Core body 14: Driven roller 18: Seat frame 18A: Side frame 18B: Front frame 18C: Rear frame 19: Pad 21: Support piece 23: Laura 24 :1st leg 24A: Joints 24B: Upper part of the first leg 24C: Lower part of the first leg 26: Contact member 27:Second leg 27A: Upper part of the second leg 27B: Lower part of second leg 28: Seat tilt sensor 29: Leg support part 31: Elastic member 34: Lever 60B: Operation panel 61A: Power switch 61B: Lift switch 61C: Movement direction switch 61D: Driving mode switch 62: Alarm device ST1: Step ST2: Step ST3: Step ST4: Step ST5: Step X: Virtual line Y: Axis line Z: Axis line

Claims

1. The body frame and a vehicle body inclination sensor provided on the vehicle body frame and detecting an inclination angle of the vehicle body frame; a drive unit coupled to the body frame, the drive unit moving the body frame along a floor surface by inverted pendulum control based on the inclination angle detected by the body inclination sensor; a seat having a seat body on which a user sits and legs extending downward, the seat being movable between a low position where the legs contact the floor surface and a high position where the legs are separated from the floor surface, and the seat being elastically coupled to the vehicle body frame; a lifting device that lifts and lowers the seat relative to the vehicle body frame; a control device for controlling the driving of the lifting device, a seat inclination sensor for detecting an inclination angle of the seat is provided on the seat; The control device determines whether or not to operate the lifting device based on the detection result of the seat inclination sensor.

2. The control device When a difference between the inclination angle of the seat acquired by the seat inclination sensor and the inclination angle of the vehicle body frame acquired by the vehicle body inclination sensor is equal to or smaller than a predetermined threshold, it is determined that the seat inclination sensor and the vehicle body inclination sensor are normal; 2. The vehicle of claim 1, wherein when a difference between the seat tilt angle acquired by the seat tilt sensor and the body tilt sensor acquired by the body tilt sensor is greater than a predetermined threshold, it is determined that either the seat tilt sensor or the body tilt sensor is malfunctioning.

3. The vehicle body frame is provided with two of the drive units, The drive units are each disk-shaped and arranged coaxially, and are supported by the vehicle body frame so as to be rotatable about an axis line.

3. The vehicle according to claim 1, wherein the vehicle body tilt sensor is positioned on an imaginary line that passes through the center of the two drive units and is perpendicular to the axis.

4. 4. The vehicle according to claim 3, wherein the seat tilt sensor is provided at a position separated from the virtual line.

5. 5. The vehicle according to claim 4, wherein the seat tilt sensor is provided in the seat body.

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