Lean vehicle and error detection method and calibration method for tilt sensor

Abstract

To enable determination of origin deviation of a tilt sensor in a lean vehicle and calibration of the tilt sensor to be easily performed.SOLUTION: A control device 36 for controlling a lean actuator 33 comprises: a self-supporting control unit 60 for controlling a lean actuator 33 so that a bank angle (detection bank angle) of a vehicle body frame 10 detected by an IMU 45 becomes zero; and a determination unit 70 for determining presence / absence of origin deviation of the IMU 45, on the basis of whether or not the detection bank angle is constant and an absolute value of output torque of the lean actuator 33 is equal to or greater than a predetermined threshold while the self-supporting control is executed.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to lean vehicles and to methods of error detection and calibration of incline sensors. [Background technology]

[0002] Conventionally, a lean vehicle having a left wheel, a right wheel, and a body frame that can be tilted with respect to the ground is known. Also, as described in International Publication No. 2020 / 045622, for example, a lean vehicle having an inclination sensor that detects the inclination angle of the body frame, a lean actuator that tilts or stands the body frame, and a control device that controls the lean actuator based on the detection result of the inclination sensor is known.

[0003] According to the lean vehicle, for example, the body frame can be made to stand on its own by controlling the lean actuator so that the inclination angle (i.e., bank angle) of the body frame from the vertical line becomes zero. That is, self-supporting control that makes the body frame stand on its own is possible. By performing self-supporting control when the lean vehicle is stopped, the body frame can be made to stand upright without the rider having to support the body frame. Also, according to the lean vehicle, the lean actuator tilts the body frame when turning left or right, allowing the rider to easily turn the lean vehicle. Thus, according to the lean vehicle, various controls are possible by utilizing the inclination sensor and lean actuator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 045622 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the inclination sensor is attached to the vehicle body frame, the position or posture of the inclination sensor may deviate from the normal position or posture. That is, an attachment error of the inclination sensor may occur. In addition, the attachment parts that attach the inclination sensor to the vehicle body frame may deteriorate over time. When the attachment parts deteriorate over time, the position or posture of the inclination sensor may deviate. When the position or posture of the inclination sensor deviates, the origin position of the inclination sensor deviates from the normal position. Hereinafter, the deviation of the origin position from the normal position is referred to as origin deviation.

[0006] If the inclination sensor is misaligned, control using the lean actuator cannot be performed well. For example, if the vehicle performs independent control without noticing that the inclination sensor is misaligned, the lean actuator will try to hold the vehicle frame in a tilted position. As a result, the vehicle frame cannot be automatically straightened.

[0007] The present invention has been made in view of the above points, and an object of the present invention is to easily determine whether or not there is a deviation in the origin of the incline sensor in a lean vehicle. Another object of the present invention is to easily calibrate the deviation in the origin of the incline sensor in a lean vehicle. [Means for solving the problem]

[0008] The lean vehicle disclosed herein includes a body frame having a head pipe, a left wheel disposed to the left of the head pipe, a right wheel disposed to the right of the head pipe, a link mechanism connecting the body frame, the left wheel, and the right wheel, an inclination sensor attached to the body frame and detecting a bank angle of the body frame, a lean actuator applying torque to the body frame about a rotation axis extending in the longitudinal direction of the vehicle, a control device receiving a signal from the inclination sensor and controlling the lean actuator, and a torque detection device detecting an output torque of the lean actuator. The control device includes an independent control unit that executes independent control to control the lean actuator so that a detected bank angle, which is the bank angle of the body frame detected by the inclination sensor, becomes zero, and a determination unit that determines the presence or absence of an origin deviation of the inclination sensor based on whether or not the detected bank angle is constant and the absolute value of the output torque of the lean actuator is equal to or greater than a predetermined threshold value when the independent control is being executed.

[0009] According to the above-mentioned lean vehicle, when there is no origin deviation in the inclination sensor, the body frame is made upright by executing self-supporting control. When the body frame is upright, gravity acts on the body frame vertically downward, so gravity does not act as a torque to tilt the body frame. Therefore, even if the absolute value of the output torque of the lean actuator is relatively small, the lean actuator can maintain the body frame in an upright position. Therefore, when there is no origin deviation in the inclination sensor, the absolute value of the output torque of the lean actuator is suppressed.

[0010] On the other hand, if the inclination sensor has an origin deviation, the control device will erroneously recognize the body frame in an inclined posture from the vertical as an upright posture. The lean actuator attempts to maintain the body frame in an inclined posture during self-support control. However, when the body frame is inclined, gravity acting on the body frame acts as a torque that tilts the body frame. Therefore, in order to maintain the posture of the body frame, the lean actuator needs to output a torque that is commensurate with that torque. The lean actuator needs to output a relatively large torque. Therefore, if the inclination sensor has an origin deviation, the absolute value of the output torque of the lean actuator becomes relatively large.

[0011] Therefore, by executing the independent control while the lean vehicle is stopped, it is possible to determine whether or not the incline sensor has an origin deviation based on the absolute value of the output torque of the lean actuator. With the above-mentioned lean vehicle, when the independent control is being executed, it is determined whether or not the detected bank angle of the incline sensor is constant and the absolute value of the output torque of the lean actuator is equal to or greater than a threshold value. With the above-mentioned lean vehicle, it is possible to easily determine whether or not the incline sensor has an origin deviation.

[0012] The control device may have a deviation amount memory unit that stores a predetermined relationship between the output torque of the lean actuator and a deviation amount of the incline sensor, and a deviation amount calculation unit that calculates the deviation amount of the incline sensor based on the output torque of the lean actuator detected by the torque detection device and the relationship stored in the deviation amount memory unit when the judgment unit determines that there is an origin deviation.

[0013] This makes it possible to quickly calculate the deviation of the incline sensor based on the output torque of the lean actuator.

[0014] The independent control unit may include an output torque storage unit storing a predetermined relationship between the detected bank angle and the output torque of the lean actuator, an output torque determination unit determining the output torque of the lean actuator based on the detected bank angle detected by the tilt sensor and the relationship stored in the output torque storage unit, and a control execution unit controlling the lean actuator to output the output torque determined by the output torque determination unit. The relationship stored in the deviation amount storage unit may be a relationship in which, when the bank angle of the body frame is B, a torque about the rotation axis of the body frame generated by gravity acting on the body frame is T, and in the relationship stored in the output torque storage unit, a deviation amount C of the tilt sensor when the output torque of the lean actuator is T is C=BA, where A is the detected bank angle when the output torque of the lean actuator is T.

[0015] The control device may have a calibration unit that calibrates the origin position of the tilt sensor from P0 to P0+ΔP when the origin position of the tilt sensor is P0 and the deviation amount calculated by the deviation amount calculation unit is ΔP.

[0016] This makes it possible to automatically calibrate the origin deviation of the tilt sensor.

[0017] The control device may have an origin position changing unit that changes an origin position of the tilt sensor when the determination unit determines that there is an origin deviation. The self-supporting control unit may be configured to execute the self-supporting control based on the changed origin position after the origin position changing unit changes the origin position. The origin position changing unit may be configured to repeatedly change the origin position of the tilt sensor until the determination unit determines that there is no origin deviation.

[0018] This makes it possible to automatically calibrate the origin deviation of the tilt sensor.

[0019] The link mechanism may include a left wheel support member supporting the left wheel, a right wheel support member arranged to the right of the left wheel support member and supporting the right wheel, a connecting member extending left and right of the body frame, a central connecting shaft extending in the front-rear direction of the vehicle and rotatably connecting the body frame to the connecting member, a left connecting shaft extending in the front-rear direction of the vehicle and rotatably connecting the left wheel support member to the connecting member, and a right connecting shaft extending in the front-rear direction of the vehicle and rotatably connecting the right wheel support member to the connecting member. The lean actuator may be configured to apply a torque about the central connecting shaft to the body frame.

[0020] The tilt sensor may be an IMU provided on the vehicle body frame.

[0021] The method for detecting an error in a tilt sensor of a lean vehicle disclosed herein includes a body frame having a head pipe, a left wheel located to the left of the head pipe, a right wheel located to the right of the head pipe, a link mechanism connecting the body frame to the left wheel and the right wheel, a tilt sensor attached to the body frame and detecting a bank angle of the body frame, a lean actuator that applies a torque about a rotation axis extending in the fore-and-aft direction of the vehicle to the body frame, and a control device that receives a signal from the tilt sensor and controls the lean actuator. The method detects an error in the tilt sensor in a lean vehicle that includes: a body frame having a head pipe, a left wheel located to the left of the head pipe, a right wheel located to the right of the head pipe, a link mechanism connecting the body frame to the left wheel and the right wheel, a tilt sensor attached to the body frame and detecting a bank angle of the body frame, a lean actuator that applies a torque to the body frame about a rotation axis extending in the fore-and-aft direction of the vehicle, and a control device that receives a signal from the tilt sensor and controls the lean actuator. The method executes independent control to control the lean actuator so that a detected bank angle, which is the bank angle of the body frame detected by the tilt sensor, becomes zero, detects an output torque of the lean actuator, and determines whether or not the tilt sensor has shifted from its origin based on whether or not the detected bank angle is constant and whether the absolute value of the output torque of the lean actuator is equal to or greater than a predetermined threshold value.

[0022] The method of calibrating a tilt sensor of a lean vehicle disclosed herein is a method of calibrating the tilt sensor in a lean vehicle including a body frame having a head pipe, a left wheel disposed to the left of the head pipe, a right wheel disposed to the right of the head pipe, a link mechanism connecting the body frame to the left wheel and the right wheel, a tilt sensor attached to the body frame and detecting the bank angle of the body frame, a lean actuator that applies a torque about a rotation axis extending in the fore-and-aft direction of the vehicle to the body frame, and a control device that receives a signal from the tilt sensor and controls the lean actuator, the lean actuator is controlled independently so that a detected bank angle, which is the lean angle, becomes zero; the output torque of the lean actuator is detected; and based on whether the detected bank angle is constant and whether the absolute value of the output torque of the lean actuator is equal to or greater than a predetermined threshold value, it is determined whether or not there is an origin deviation of the incline sensor; when it is determined that there is an origin deviation of the incline sensor, an amount of deviation ΔP of the incline sensor is calculated based on the output torque of the lean actuator and a predetermined relationship between the output torque of the lean actuator and the amount of deviation of the incline sensor; and when the origin position of the incline sensor is set to P0, the origin position of the incline sensor is calibrated from P0 to P0+ΔP.

[0023] The method of calibrating a tilt sensor of a lean vehicle disclosed herein is a method of calibrating the tilt sensor in a lean vehicle that includes a body frame having a head pipe, a left wheel disposed to the left of the head pipe, a right wheel disposed to the right of the head pipe, a link mechanism that connects the body frame to the left wheel and the right wheel, a tilt sensor attached to the body frame and detecting a bank angle of the body frame, a lean actuator that applies a torque about a rotation axis extending in the fore-and-aft direction of the vehicle to the body frame, and a control device that receives a signal from the tilt sensor and controls the lean actuator, the lean actuator is controlled so that a detected bank angle, which is the bank angle of the vehicle body frame detected by a torque detector, becomes zero; output torque of the lean actuator is detected; and based on whether the detected bank angle is constant and whether the absolute value of the output torque of the lean actuator is equal to or greater than a predetermined threshold value, a determination is made as to whether or not there is an origin deviation of the incline sensor; when it is determined that there is an origin deviation of the incline sensor, the origin position of the incline sensor is changed, the autonomous control is performed based on the changed origin position, and the determination as to whether or not there is an origin deviation, the change of the origin position, and the execution of the autonomous control are repeated until it is determined that there is no origin deviation. Effect of the Invention

[0024] According to the present invention, it is possible to easily determine whether or not there is a deviation of the origin of the incline sensor of a lean vehicle. Also, it is possible to easily calibrate the deviation of the origin of the incline sensor of a lean vehicle. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a left side view of a lean vehicle according to one embodiment. [Diagram 2] FIG. 2 is a left side view of a portion of a lean vehicle. [Diagram 3] FIG. 3 is a left side view of a portion of a lean vehicle. [Figure 4] FIG. 4 is a front view of a portion of a lean vehicle. [Diagram 5] FIG. 5 is a plan view of a portion of a lean vehicle. [Figure 6] FIG. 6 is a front view of a portion of the lean vehicle when the body frame is tilted to the left. [Figure 7] FIG. 7 is a schematic front view of a vehicle body frame when self-sustaining control is performed when there is no deviation of the origin of the IMU. [Figure 8] FIG. 8 is a schematic front view of a vehicle body frame when self-sustaining control is performed when there is a deviation in the origin of the IMU. [Figure 9] FIG. 9 is a block diagram of the control device. [Figure 10] FIG. 10 is a block diagram of the independent control unit according to the first embodiment. [Figure 11] FIG. 11 is a diagram showing the relationship between the detected bank angle, the actual bank angle, and the amount of deviation. [Figure 12] FIG. 12 is a map showing the relationship between the output torque of the lean actuator and the deviation amount. [Figure 13] FIG. 13 is a flowchart relating to determination and calibration of an origin shift of the IMU according to the first embodiment. [Figure 14] FIG. 14 is a block diagram of a self-supporting control unit according to the second embodiment. [Figure 15] FIG. 15 is a flowchart relating to determination and calibration of an origin shift of an IMU according to the second embodiment. [Figure 16] FIG. 16 is a flowchart showing an example of a method for changing the origin position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] (First embodiment) Hereinafter, an embodiment of a lean vehicle will be described with reference to the drawings. FIG. 1 is a left side view of a lean vehicle 1 according to this embodiment. FIG. 2 is a left side view of a portion of the lean vehicle 1. FIG. 3 is a left side view of a portion of the lean vehicle 1. FIG. 4 is a front view of a portion of the lean vehicle 1. FIG. 5 is a plan view of a portion of the lean vehicle 1. FIG. 6 is a front view of a portion of the lean vehicle 1 when the lean vehicle 1 is tilted to the left.

[0027] In the following explanation, unless otherwise specified, front, rear, left, right, top, and bottom refer to the front, rear, left, right, top, and bottom as seen by a virtual occupant sitting on the seat 5 when the lean vehicle 1, with no occupant and no luggage on board, is stopped in an upright position on a horizontal plane (note that the upright position here refers to a position in which the body frame 10, which will be described later, is upright). In the drawings, F, Rr, L, R, U, and D represent the front, rear, left, right, top, and bottom, respectively.

[0028] 1 and 2, the lean vehicle 1 includes a body frame 10, a link mechanism 20, a left front wheel 3L, a right front wheel 3R (see FIG. 4), a rear wheel 4, a power unit 2, a seat 5, and a storage box 16. The lean vehicle 1 is a three-wheeled vehicle that includes two front wheels 3L, 3R and one rear wheel 4.

[0029] As shown in FIG. 2, the body frame 10 has a head pipe 11, a down frame 12 extending rearward and downward from the head pipe 11, and a seat frame 13 extending rearward from the down frame 12. A seat 5 is supported by the body frame 10. Here, the seat 5 is supported by the seat frame 13. A storage box 16 is disposed below the seat 5 and supported by the seat frame 13. As shown in FIG. 4, a steering shaft 14 is rotatably supported by the head pipe 11. A steering handle 15 is fixed to the steering shaft 14. An accelerator grip 15R is provided at the right end of the steering handle 15, and a left grip 15L is provided at the left end of the steering handle 15.

[0030] As shown in FIG. 1, the lean vehicle 1 according to this embodiment is a scooter. The lean vehicle 1 is equipped with a low-floor footrest 7. The footrest 7 is supported by a body frame 10. Here, the footrest 7 is supported by a down frame 12 (see FIG. 2). The footrest 7 is disposed below the seat 5. The footrest 7 is a platform that supports the feet of a rider sitting on the seat 5.

[0031] 4, the link mechanism 20 is a four-joint parallel link type link mechanism. The link mechanism 20 is disposed above the left front wheel 3L and the right front wheel 3R. The link mechanism 20 has an upper arm 21, a lower arm 22, a left arm 23, and a right arm 24.

[0032] The upper arm 21 and the lower arm 22 extend to the left and right. The upper arm 21 and the lower arm 22 are examples of connecting members extending to the left and right of the body frame 10. The lower arm 22 is disposed below the upper arm 21. The upper arm 21 and the lower arm 22 are disposed in front of the head pipe 11 (see FIG. 2). The upper arm 21 is rotatably connected to the head pipe 11 by a first central connecting shaft 21Cc extending in the vehicle fore-and-aft direction. The lower arm 22 is rotatably connected to the head pipe 11 by a second central connecting shaft 22Cc extending in the vehicle fore-and-aft direction.

[0033] In this embodiment, as shown in FIG. 2, another lower arm 22B is disposed behind the head pipe 11. The lower arm 22B extends to the left and right. The lower arm 22B is disposed below the upper arm 21. The lower arm 22B is rotatably connected to the head pipe 11 by a third central connecting shaft 23Cc (see FIG. 3) extending in the vehicle front-rear direction. Note that another upper arm (not shown) may be disposed behind the head pipe 11, and this upper arm may be rotatably connected to the head pipe 11 by another central connecting shaft (not shown) extending in the vehicle front-rear direction. However, the other upper arm and the other lower arm 22B disposed behind the head pipe 11 are not necessarily required.

[0034] As shown in Fig. 4, the left arm 23 and the right arm 24 extend upward and downward. The left arm 23 is disposed to the left of the head pipe 11, and the right arm 24 is disposed to the right of the head pipe 11. The right arm 24 is disposed to the right of the left arm 23. The left arm 23 and the right arm 24 are disposed rearward of the upper arm 21 and the lower arm 22. The left arm 23 and the right arm 24 are disposed in front of the lower arm 22B. The left arm 23 and the right arm 24 are rotatably connected to the upper arm 21, the lower arm 22, and the lower arm 22B.

[0035] In detail, the upper end of the left arm 23 is rotatably connected to the left end of the upper arm 21 by a first left connecting shaft 21Lc extending in the vehicle front-rear direction. The lower end of the left arm 23 is rotatably connected to the left end of the lower arm 22 by a second left connecting shaft 22Lc extending in the vehicle front-rear direction. The lower end of the left arm 23 is rotatably connected to the left end of the lower arm 22B by a third left connecting shaft (not shown) extending in the vehicle front-rear direction. The upper end of the right arm 24 is rotatably connected to the right end of the upper arm 21 by a first right connecting shaft 21Rc extending in the vehicle front-rear direction. The lower end of the right arm 24 is rotatably connected to the right end of the lower arm 22 by a second right connecting shaft 22Rc extending in the vehicle front-rear direction. The lower end of the right arm 24 is rotatably connected to the right end of the lower arm 22B by a third right connecting shaft (not shown) extending in the vehicle front-rear direction.

[0036] The lean vehicle 1 includes a left suspension 25L and a right suspension 25R. In this embodiment, the left suspension 25L and the right suspension 25R are telescopic suspensions. The upper end of the left suspension 25L and the upper end of the right suspension 25R are connected to the link mechanism 20. The lower end of the left suspension 25L is connected to the left front wheel 3L, and the lower end of the right suspension 25R is connected to the right front wheel 3R. In detail, the upper end of the left suspension 25L is connected to the lower end of the left arm 23 via the left bracket 26L. The upper end of the left suspension 25L is connected to the left arm 23 so as to be rotatable in the left-right direction of the vehicle body frame 10. The upper end of the right suspension 25R is connected to the lower end of the right arm 24 via the right bracket 26R. The upper end of the right suspension 25R is connected to the right arm 24 so as to be rotatable in the left-right direction of the vehicle body frame 10.

[0037] The left suspension 25L, the left bracket 26L, and the left arm 23 constitute a left wheel support member 19L that supports the left front wheel 3L. The right suspension 25R, the right bracket 26R, and the right arm 24 constitute a right wheel support member 19R that supports the right front wheel 3R.

[0038] A center plate 27C is fixed to the lower end of the steering shaft 14. As shown in FIG. 5, the center plate 27C extends forward from the steering shaft 14. A left plate 27L is fixed to the left bracket 26L. A right plate 27R is fixed to the right bracket 26R. The left plate 27L, the center plate 27C, and the right plate 27R are connected to a tie rod 28 so as to be rotatable left and right. The steering shaft 14 is connected to the left arm 23 and the right arm 24 via the center plate 27C, the tie rod 28, the left plate 27L, and the right plate 27R.

[0039] As shown in FIG. 3, the lean vehicle 1 includes a control unit 30 that controls the bank angle. In addition, the control unit 30 is not shown in any of the figures other than FIG. 3. The bank angle here refers to the inclination angle θ (see FIG. 6) of the vehicle body frame 10 from the vertical line. In this embodiment, the bank angle θ coincides with the angle between the axis of the head pipe 11 and the vertical line when viewed from the front of the vehicle. The control unit 30 controls the bank angle of the vehicle body frame 10 by adjusting the rotation of the upper arm 21 and the lower arm 22 relative to the vehicle body frame 10. The control unit 30 is configured to apply torque to at least one of the upper arm 21 and the lower arm 22. The control unit 30 is connected to at least one of the upper arm 21 and the lower arm 22 and the vehicle body frame 10. In this embodiment, the control unit 30 is connected to the upper arm 21 and the head pipe 11. However, this is not particularly limited, and the control unit 30 may be connected to the lower arm 22 and the head pipe 11.

[0040] The control unit 30 includes a case 31 , a lean actuator 33 , a gear 35 A, and a gear 35 B arranged inside the case 31 , and a control device 36 arranged inside the case 31 .

[0041] The lean actuator 33 is a power source that applies torque around the first central connecting shaft 21Cc to the body frame 10. The lean actuator 33 may apply torque directly or indirectly to the body frame 10. In this embodiment, the lean actuator 33 applies a left-handed or right-handed torque to the upper arm 21, thereby indirectly applying a right-handed or left-handed torque to the body frame 10. In this embodiment, the lean actuator 33 is configured by an electric motor. However, the lean actuator 33 is not limited to an electric motor as long as it generates power.

[0042] The lean actuator 33 is connected to a gear 35A, and the gear 35A meshes with a gear 35B. The gears 35A and 35B form a reduction gear. The gear 35B is fixed to an output shaft 34. The output shaft 34 is a rotating shaft that rotates when driven by the lean actuator 33, and is connected to the upper arm 21. The torque of the lean actuator 33 is transmitted to the upper arm 21 via the gears 35A, 35B, and the output shaft 34. When the lean actuator 33 is driven, a torque is applied to the upper arm 21 around the first central connecting shaft 21Cc (see FIG. 4). Since the upper arm 21 is connected to the body frame 10 so as to be rotatable around the first central connecting shaft 21Cc, when a torque is applied to the upper arm 21 around the first central connecting shaft 21Cc, a torque is generated in the body frame 10 around the first central connecting shaft 21Cc. In this embodiment, the number of gears interposed between the lean actuator 33 and the output shaft 34 is two, but the number of gears is not limited in any way.

[0043] The lean vehicle 1 is equipped with an IMU (inertial measurement unit) 45 attached to the body frame 10 (see FIG. 2). The IMU 45 is an example of an inclination sensor that detects the bank angle of the body frame 10. In this embodiment, the IMU 45 is attached to the rear of the body frame 10. However, the installation location of the IMU 45 is not particularly limited. The IMU 45 may be attached to the front of the body frame 10, for example. The IMU 45 may be directly attached to the body frame 10, or indirectly attached to the body frame 10 via a part such as a bracket.

[0044] The control device 36 is communicatively connected to the IMU 45 via a wire harness (not shown). The control device 36 is configured to receive a signal from the IMU 45 and control the lean actuator 33. The control device 36 is configured by a computer having a CPU, ROM, and RAM (not shown).

[0045] As shown in FIG. 2, the power unit 2 is supported by the body frame 10 so as to be able to swing. The power unit 2 is connected to the rear wheels 4 so as to be able to transmit power. The power unit 2 generates driving force for traveling. The power unit 2 imparts power to the rear wheels 4. The power unit 2 may include an internal combustion engine or an electric motor. In this embodiment, the power unit 2 includes an internal combustion engine.

[0046] The lean-to vehicle 1 is equipped with left and right rear suspensions 50. The left rear suspension 50 is disposed to the left of the rear wheel 4, and the right rear suspension 50 is disposed to the right of the rear wheel 4. Each rear suspension 50 has an upper support portion 51 supported to be swingable on the body frame 10, and a lower support portion 52 supported to be swingable with respect to the rear wheel 4. Here, the upper support portion 51 is swingably supported on the seat frame 13 via a bracket 13B. The lower support portion 52 is swingably supported on a bracket 4B attached to the axle of the rear wheel 4.

[0047] In the lean vehicle 1, various controls are possible by the control device 36 controlling the lean actuator 33. For example, the control device 36 can execute self-support control to automatically keep the body frame 10 in an upright position while the lean vehicle 1 is stopped. The control performed by the control device 36 is executed based on the bank angle detected by the IMU 45.

[0048] Incidentally, when the IMU 45 is directly or indirectly attached to the body frame 10, the position of the IMU 45 may deviate from the normal position, or the attitude of the IMU 45 may tilt from the normal attitude. In addition, the attachment parts (e.g., brackets, etc.) that attach the IMU 45 to the body frame 10 may deteriorate over time. The deterioration of the attachment parts over time may cause the position or attitude of the IMU 45 to deviate from the normal position or attitude. Here, if the position or attitude of the IMU 45 deviates, the origin position of the IMU 45 will deviate from the normal position. That is, an origin deviation occurs in the IMU 45.

[0049] If the IMU 45 has an origin deviation, the control executed based on the detection result of the IMU 45 cannot be executed satisfactorily. Therefore, it is important to know whether the IMU 45 has an origin deviation. Here, in order to determine whether the IMU 45 has an origin deviation, it is conceivable to periodically bring the lean vehicle 1 to an inspection site and inspect the origin deviation using an inspection device provided at the inspection site. However, such an inspection takes time and effort.

[0050] According to this embodiment, such labor and time can be reduced. As described below, the lean vehicle 1 according to this embodiment has a function of determining whether or not there is an origin deviation of the bank angle of the IMU 45. The lean vehicle 1 also has a function of automatically calibrating the origin deviation of the bank angle of the IMU 45. According to this embodiment, it is possible to easily determine whether or not there is an origin deviation of the bank angle of the IMU 45 and calibrate it. Next, a method of determining and calibrating the origin deviation of the bank angle of the IMU 45 (hereinafter simply referred to as "origin deviation") will be described.

[0051] When there is no origin deviation in the IMU 45, the bank angle detected by the IMU 45 and the actual bank angle of the body frame 10 match. Hereinafter, the bank angle detected by the IMU 45 is referred to as the "detected bank angle," and the actual bank angle of the body frame 10 is referred to as the "actual bank angle." As shown in FIG. 7, when there is no origin deviation, the body frame 10 stands upright when the self-support control is executed. Since the gravity G acting on the body frame 10 acts vertically downward, when the body frame 10 stands upright, the gravity G does not act as a torque that tilts the body frame 10. Therefore, even if the output torque of the lean actuator 33 is relatively small, the lean actuator 33 can maintain the body frame 10 in an upright position. Therefore, when there is no origin deviation, the output torque of the lean actuator 33 is suppressed.

[0052] On the other hand, when an origin deviation occurs, the detected bank angle does not match the actual bank angle. When an origin deviation occurs, as shown in an exaggerated manner in FIG. 8, the detected bank angle becomes zero when the body frame 10 is tilted from the vertical line VL. The control device 36 controls the lean actuator 33 during self-sustaining control so that the detected bank angle becomes zero. Therefore, the control device 36 tries to maintain the body frame 10 in a tilted posture. However, when the body frame 10 is tilted, the gravity G acting on the body frame 10 acts as a torque that tilts the body frame 10. More specifically, the vector component Gr of the gravity G in the direction perpendicular to the vehicle up-down direction of the body frame 10 acts as a torque that tilts the body frame 10. Therefore, the lean actuator 33 needs to output a torque that is commensurate with the torque in order to maintain the posture of the body frame 10 (in other words, to prevent the body frame 10 from falling over). The lean actuator 33 needs to output a relatively large torque. Therefore, when an origin deviation occurs, the output torque of the lean actuator 33 becomes relatively large.

[0053] Therefore, by executing the autonomous control while the lean vehicle 1 is stopped, it is possible to determine whether or not there is an origin deviation of the IMU 45 based on the magnitude of the output torque of the lean actuator 33. The control device 36 according to this embodiment has the following configuration in order to determine whether or not there is an origin deviation and to perform calibration.

[0054] As shown in Fig. 9, the lean vehicle 1 is provided with a torque detection device 47 that detects the output torque of the lean actuator 33. In this embodiment, the output torque of the lean actuator 33 is positive when the vehicle body frame 10 is driven rightward, and negative when the vehicle body frame 10 is driven leftward. However, the positive and negative directions may be reversed. The control device 36 has an independent control unit 60 that executes independent control, a determination unit 70 that determines whether or not there is an origin deviation, a deviation amount storage unit 71, a deviation amount calculation unit 72, and a calibration unit 73 that calibrates the origin deviation.

[0055] During execution of autonomous control, the determination unit 70 determines whether or not there is an origin deviation of the bank angle of the IMU 45 based on whether or not the detected bank angle is constant and the absolute value of the output torque of the lean actuator 33 is equal to or greater than a predetermined threshold. The determination unit 70 determines that there is an origin deviation when the absolute value of the output torque is equal to or greater than the threshold, and determines that there is no origin deviation when the absolute value of the output torque is less than the threshold.

[0056] The independent control unit 60 controls the lean actuator 33 so that the bank angle detected by the IMU 45 becomes zero. When the body frame 10 tilts, the lean actuator 33 outputs torque to raise the body frame 10. Here, the lean actuator 33 must output a larger torque as the bank angle of the body frame 10 becomes larger. The magnitude of the torque that the lean actuator 33 must output can be specified in advance by testing or calculation according to the bank angle. As shown in FIG. 10, the independent control unit 60 has an output torque storage unit 61 that stores a relationship (hereinafter referred to as a first relationship) between a predetermined detected bank angle and the output torque of the lean actuator 33. The output torque storage unit 61 is composed of, for example, a memory. The independent control unit 60 also has an output torque determination unit 62 and a control execution unit 63. The output torque determination unit 62 receives a signal from the IMU 45 and determines the output torque of the lean actuator 33 based on the detected bank angle detected by the IMU 45 and the first relationship stored in the output torque storage unit 61. The control execution unit 63 controls the lean actuator 33 so as to output the output torque determined by the output torque determination unit 62 .

[0057] The deviation amount storage unit 71 stores a predetermined relationship (hereinafter, referred to as a second relationship) between the output torque of the lean actuator 33 and the deviation amount of the bank angle of the IMU 45. The second relationship can be specified, for example, as follows.

[0058] As described above, when the body frame 10 is tilted, gravity acting on the body frame 10 acts as a torque that tilts the body frame 10 (see FIG. 8). When the body frame 10 is tilted, gravity generates a torque on the body frame 10 about a rotation axis extending in the front-rear direction of the vehicle. This torque varies depending on the actual bank angle of the body frame 10, but can be specified in advance by testing or calculation. Hereinafter, the relationship between the actual bank angle and the torque acting on the body frame 10 will be referred to as the third relationship. Here, as shown in FIG. 11, when the actual bank angle of the body frame 10 is B, the torque acting on the body frame 10 due to gravity is defined as T.

[0059] When the output torque TA of the lean actuator 33 and the torque G are balanced during self-sustaining control, the body frame 10 stops in a tilted position. At this time, the detected bank angle detected by the IMU 45 becomes constant. During self-sustaining control, the lean actuator 33 outputs a torque corresponding to the detected bank angle. The output torque of the lean actuator 33 is determined based on the detected bank angle and a first relationship stored in the output torque storage unit 61. Here, based on the first relationship, it is assumed that when the detected bank angle is A, the output torque of the lean actuator 33 is TA.

[0060] If the deviation amount of the origin of the bank angle of the IMU 45 is C, when the detected bank angle is A, the actual bank angle B is B=A+C. Therefore, the deviation amount C=BA. The torque T generated by gravity is equal to the output torque TA of the lean actuator 33. The output torque TA of the lean actuator 33 is detected by the torque detection device 47. Therefore, the torque T caused by gravity can be detected by the torque detection device 47. If the torque T is known, the actual bank angle B can be determined from the torque T and the third relationship. In addition, the detected bank angle A can be determined from the output torque TA of the lean actuator 33 detected by the torque detection device 47 and the first relationship. Therefore, the deviation amount C can be determined based on the output torque TA of the lean actuator 33.

[0061] In this manner, the relationship (second relationship) between the output torque TA of the lean actuator 33 and the deviation amount C can be specified in advance. For example, as shown in Fig. 12, the relationship between the output torque TA and the deviation amount C can be stored in advance in the deviation amount storage unit 71 as a map.

[0062] When the judgment unit 70 judges that there is an origin deviation, the deviation calculation unit 72 calculates the deviation of the IMU 45 based on the output torque of the lean actuator 33 detected by the torque detection device 47 and the second relationship stored in the deviation memory unit 71.

[0063] When the origin position of the bank angle of the IMU 45 is P0 and the deviation calculated by the deviation amount calculation unit 72 is ΔP, the calibration unit 73 calibrates the origin position of the bank angle of the IMU 45 from P0 to P0+ΔP.

[0064] The above is the configuration of the lean vehicle 1. The output torque determination unit 62 and the control execution unit 63 of the independent control unit 60, the judgment unit 70, the deviation amount calculation unit 72, and the calibration unit 73 are generated by, for example, a computer CPU executing a computer program. The output torque storage unit 61 and the deviation amount storage unit 71 of the independent control unit 60 are configured by, for example, a computer memory. Next, a method of judging whether or not there is an origin deviation of the IMU 45 and a method of calibration will be described with reference to the flowchart of FIG. 13.

[0065] The determination of the presence or absence of origin deviation and the calibration are performed in a state where the lean vehicle 1 is stopped on a horizontal plane. First, in step S1, the autonomous control unit 60 starts autonomous control. Next, in step S2, the determination unit 70 determines whether the detected bank angle detected by the IMU 45 is constant or not. If the determination result is YES, the process proceeds to step S3. In step S3, the torque detection device 47 detects the output torque of the lean actuator 33. Note that, in this example, step S3 is performed after step S2, but the order of steps S2 and S3 is not particularly limited. In step S4, the determination unit 70 determines whether the absolute value of the output torque is equal to or greater than a threshold value. If the determination result in step S4 is YES, the process proceeds to step S5, where it is determined that there is an origin deviation. If the determination result in step S4 is NO, the process proceeds to step S8, where it is determined that there is no origin deviation.

[0066] If it is determined that there is an origin deviation, the process proceeds to step S6. In step S6, the deviation calculation unit 72 calculates the deviation of the bank angle of the IMU 45 based on the output torque and the second relationship stored in the deviation storage unit 71. Next, the process proceeds to step S7, where the calibration unit 73 calibrates the origin position from P0 to P0+ΔP, where P0 is the origin position of the bank angle of the IMU 45 and ΔP is the deviation.

[0067] In this manner, the bank angle of the IMU 45 is automatically calibrated. Thereafter, the lean vehicle 1 can execute various controls using the calibrated IMU 45.

[0068] As described above, according to this embodiment, by executing autonomous control while the lean vehicle 1 is stopped, it is possible to determine whether or not there is an origin deviation of the bank angle of the IMU 45 based on the magnitude of the output torque of the lean actuator 33. It is not necessary to bring the lean vehicle 1 into an inspection site equipped with an inspection device in order to determine whether or not there is an origin deviation of the IMU 45. No special inspection device is required to determine whether or not there is an origin deviation of the IMU 45. According to this embodiment, it is possible to easily determine whether or not there is an origin deviation of the IMU 45.

[0069] According to this embodiment, the control device 36 has a deviation amount storage unit 71 and a deviation amount calculation unit 72. The deviation amount storage unit 71 stores a predetermined relationship (second relationship) between the output torque of the lean actuator 33 and the deviation amount of the IMU 45. When the determination unit 70 determines that there is an origin deviation, the deviation amount calculation unit 72 calculates the deviation amount of the IMU 45 based on the output torque of the lean actuator 33 and the second relationship. According to this embodiment, the deviation amount of the IMU 45 can be quickly calculated.

[0070] According to this embodiment, after the deviation amount calculation unit 72 calculates the deviation amount, the calibration unit 73 calibrates the origin position of the IMU 45. Therefore, the origin deviation of the bank angle of the IMU 45 can be automatically calibrated.

[0071] Second embodiment In the above embodiment, the deviation amount calculation unit 72 calculates the deviation amount, and the calibration unit 73 calibrates the origin position of the IMU 45 based on the deviation amount. However, the deviation amount calculation unit 72 may be omitted. The second embodiment described below is an embodiment in which the method of calibrating the origin position in the first embodiment is changed.

[0072] 14, the control device 36 according to the second embodiment has an origin position changing unit 75 instead of the deviation amount storage unit 71, the deviation amount calculation unit 72, and the calibration unit 73. When the determination unit 70 determines that there is an origin deviation, the origin position changing unit 75 changes the origin position of the IMU 45. The origin position changing unit 75 repeats changing the origin position until the determination unit 70 determines that there is no origin deviation. Note that the origin position changing unit 75 is generated, for example, by the CPU of a computer executing a computer program.

[0073] FIG. 15 is a flowchart of the origin deviation calibration method according to the second embodiment. Steps S1 to S5 and S8 are the same as those in the first embodiment. In this embodiment, after it is determined in step S5 that there is an origin deviation, the process proceeds to step S20, where the origin position is changed by the origin position change unit 75. After the origin position is changed, the process returns to step S2, and the processes from step S2 onwards are repeated. In step S4, it is determined again based on the changed origin position whether the absolute value of the output torque of the lean actuator 33 is equal to or greater than the threshold value. If the output torque is equal to or greater than the threshold value, it is determined in step S5 that there is an origin deviation, and the process proceeds again to step S20. Thereafter, the above processes are repeated until it is determined that there is no origin deviation (step S8).

[0074] The change of the origin position in step S20 can be performed, for example, as follows. As shown in FIG. 16, in this embodiment, after step S5, in step S21, it is determined whether the output torque of the lean actuator 33 is greater than 0. Note that, in this embodiment as well, the output torque of the lean actuator 33 is positive when driving the body frame 10 to the right and negative when driving the body frame 10 to the left. When the body frame 10 is inclined to the left of the vertical line, the lean actuator 33 drives the body frame 10 to the right, so the output torque is greater than 0. When the body frame 10 is inclined to the right of the vertical line, the lean actuator 33 drives the body frame 10 to the left, so the output torque is less than 0.

[0075] If the result of the determination in step S21 is that the output torque is greater than 0, the process proceeds to step S22. In step S22, the origin position P0 is set to P0-Δ / 2 n-1 Here, Δ is a predetermined constant, and n represents the number of times step S20 is repeated. When step S20 is executed for the first time, n=1, so the origin position P0 is changed to P0-Δ. If it is determined in step S21 that the output torque is smaller than 0, the process proceeds to step S23. In step S23, the origin position P0 is changed to P0+Δ / 2 n-1will be changed to.

[0076] After step S22 or S23, the process proceeds to step S24, where the number of repetitions is incremented by 1. That is, n is changed to n+1. Then, the process returns to step S4.

[0077] The above is an example of the specific process of step S20. However, the above process is merely an example, and the specific process of step S20 is not particularly limited.

[0078] In this embodiment as well, it is possible to automatically calibrate the origin deviation of the bank angle of the IMU 45. Furthermore, according to this embodiment, the deviation amount storage unit 71 and the deviation amount calculation unit 72 are not necessary.

[0079] (Other embodiments) Although the first and second embodiments have been described above, the above-mentioned embodiments are merely examples, and various other embodiments are possible.

[0080] The inclination sensor that detects the bank angle of the body frame 10 is not limited to the IMU 45 .

[0081] The control device 36 does not have to be disposed inside the control unit 30. The location of the control device 36 is not limited to the front part of the lean vehicle 1. The control device 36 may be separate from the control device that controls the power unit 2, or may be integrated with the control device.

[0082] In the error detection method according to each of the above-mentioned embodiments, the determination of the origin deviation of the IMU 45 is executed by the control device 36, but the determination of the origin deviation may be performed by a person. For example, a mechanic of the lean vehicle 1 may determine the origin deviation of the IMU 45 based on whether the detected bank angle is constant and the absolute value of the output torque of the lean actuator 33 is equal to or greater than a threshold value. When a mechanic or the like makes the determination, the second relationship does not necessarily need to be stored in a computer, and may be described in, for example, a work manual. The mechanic or the like can make the above-mentioned determination while referring to the work manual. In addition, the calibration method according to each of the above-mentioned embodiments is executed by the control device 36, but may be performed by a person such as a mechanic. For example, in the first embodiment, the mechanic or the like may perform the calibration while referring to a work manual in which the third relationship is described. In the second embodiment, the mechanic or the like may change the origin position while visually checking the state of the lean vehicle 1.

[0083] The lean vehicle is not limited to a three-wheeled vehicle having a left front wheel 3L, a right front wheel 3R, and a rear wheel 4. The lean vehicle may be a three-wheeled vehicle having a front wheel, a left rear wheel, and a right rear wheel. The lean vehicle is not limited to a scooter. The lean vehicle may be a saddle-type vehicle other than a scooter. Note that a saddle-type vehicle is a vehicle on which a rider straddles and rides. [Explanation of symbols]

[0084] Reference Signs List 1... lean vehicle, 3L... left front wheel (left wheel), 3R... right front wheel (right wheel), 10... vehicle body frame, 11... head pipe, 19L... left wheel support member, 19R... right wheel support member, 20... link mechanism, 21... connecting member, 21Cc... first central connecting shaft (central connecting shaft), 21Lc... first left connecting shaft (left connecting shaft), 21Rc... first right connecting shaft (right connecting shaft), 33... lean actuator, 36... control device, 45... IMU (inclination sensor), 47... torque detection device, 60... independent control unit, 61... output torque storage unit, 62... output torque determination unit, 63... control execution unit, 70... determination unit, 71... deviation amount storage unit, 72... deviation amount calculation unit, 73... calibration unit, 75... origin position change unit

Claims

1. a body frame having a head pipe; A left wheel disposed to the left of the head pipe; A right wheel disposed to the right of the head pipe; a link mechanism connecting the body frame to the left wheel and the right wheel; an inclination sensor attached to the vehicle body frame and detecting a bank angle of the vehicle body frame; a lean actuator that applies a torque about a rotation axis extending in a front-rear direction of the vehicle to the body frame; A control device that receives a signal from the tilt sensor and controls the lean actuator; a torque detection device for detecting an output torque of the lean actuator, The control device includes: an independent control unit that executes independent control to control the lean actuator so that a detected bank angle, which is a bank angle of the vehicle body frame detected by the inclination sensor, becomes zero; and a determination unit that determines whether or not the inclination sensor has shifted from its origin based on whether or not the detected bank angle is constant and the absolute value of the output torque of the lean actuator is equal to or greater than a predetermined threshold value when the independent control is being performed.

2. The control device includes: a deviation amount storage unit that stores a predetermined relationship between the output torque of the lean actuator and a deviation amount of the tilt sensor; a deviation amount calculation unit that calculates a deviation amount of the inclination sensor based on the output torque of the lean actuator detected by the torque detection device and the relationship stored in the deviation amount storage unit when the determination unit determines that there is an origin deviation; 2. The lean vehicle of claim 1, further comprising:

3. The independent control unit includes: an output torque storage unit that stores a predetermined relationship between the detected bank angle and an output torque of the lean actuator; an output torque determination unit that determines an output torque of the lean actuator based on the detected bank angle detected by the tilt sensor and the relationship stored in the output torque storage unit; a control execution unit that controls the lean actuator so as to output the output torque determined by the output torque determination unit, The relationship stored in the deviation amount storage unit is When the bank angle of the body frame is B, a torque around the rotation axis of the body frame generated by gravity acting on the body frame is defined as T, In the relationship stored in the output torque storage unit, when the detected bank angle when the output torque of the lean actuator is T is A, 3. The lean vehicle according to claim 2, wherein the amount of deviation C of the inclination sensor when the output torque of the lean actuator is T satisfies the relationship C=B-A.

4. 4. The lean vehicle according to claim 2 or 3, wherein the control device has a calibration unit that calibrates the origin position of the incline sensor from P0 to P0 + ΔP when the origin position of the incline sensor is P0 and the deviation amount calculated by the deviation amount calculation unit is ΔP.

5. the control device has an origin position changing unit that changes an origin position of the tilt sensor when the determining unit determines that there is an origin deviation; the self-supporting control unit is configured to execute the self-supporting control based on the changed origin position after the origin position changing unit changes the origin position, 2. The lean vehicle according to claim 1, wherein the origin position changing unit is configured to repeatedly change the origin position of the incline sensor until the determining unit determines that there is no origin deviation.

6. The link mechanism includes: a left wheel support member for supporting the left wheel; a right wheel support member disposed to the right of the left wheel support member and supporting the right wheel; a connecting member extending to the left and right of the body frame; a central connecting shaft extending in a vehicle front-rear direction and rotatably connecting the body frame to the connecting member; a left connecting shaft extending in a vehicle front-rear direction and rotatably connecting the left wheel support member to the connecting member; a right connecting shaft extending in a front-rear direction of the vehicle and rotatably connecting the right wheel support member to the connecting member, The lean vehicle according to claim 1 , wherein the lean actuator is configured to apply a torque about the central connecting shaft to the vehicle body frame.

7. The lean vehicle according to claim 1 , wherein the tilt sensor is an IMU provided on the vehicle body frame.

8. a body frame having a head pipe; A left wheel disposed to the left of the head pipe; A right wheel disposed to the right of the head pipe; a link mechanism connecting the body frame to the left wheel and the right wheel; an inclination sensor attached to the vehicle body frame and detecting a bank angle of the vehicle body frame; a lean actuator that applies a torque about a rotation axis extending in a front-rear direction of the vehicle to the body frame; A control device that receives a signal from the tilt sensor and controls the lean actuator; A method for detecting an error in the tilt sensor in a lean vehicle comprising: and executing an independent control for controlling the lean actuator so that a detected bank angle, which is a bank angle of the vehicle body frame detected by the inclination sensor, becomes zero. Detecting an output torque of the lean actuator; A method for detecting an error in a lean vehicle inclination sensor, the method determining whether or not the inclination sensor has shifted from its origin based on whether the detected bank angle is constant and whether the absolute value of the output torque of the lean actuator is equal to or greater than a predetermined threshold.

9. a body frame having a head pipe; A left wheel disposed to the left of the head pipe; A right wheel disposed to the right of the head pipe; a link mechanism connecting the body frame to the left wheel and the right wheel; an inclination sensor attached to the vehicle body frame and detecting a bank angle of the vehicle body frame; a lean actuator that applies a torque about a rotation axis extending in a front-rear direction of the vehicle to the body frame; A control device that receives a signal from the tilt sensor and controls the lean actuator; A method for calibrating the tilt sensor in a lean vehicle comprising: and executing an independent control for controlling the lean actuator so that a detected bank angle, which is a bank angle of the vehicle body frame detected by the inclination sensor, becomes zero. Detecting an output torque of the lean actuator; determining whether or not the origin of the tilt sensor is shifted based on whether or not the detected bank angle is constant and whether or not an absolute value of the output torque of the lean actuator is equal to or greater than a predetermined threshold value; when it is determined that there is an origin deviation of the tilt sensor, a deviation amount ΔP of the tilt sensor is calculated based on an output torque of the lean actuator and a predetermined relationship between the output torque of the lean actuator and an origin deviation amount of the tilt sensor; A method for calibrating an inclination sensor of a lean vehicle, the method comprising the steps of: calibrating an origin position of the inclination sensor from P0 to P0+ΔP, where P0 is an origin position of the inclination sensor.

10. a body frame having a head pipe; A left wheel disposed to the left of the head pipe; A right wheel disposed to the right of the head pipe; a link mechanism connecting the body frame to the left wheel and the right wheel; an inclination sensor attached to the vehicle body frame and detecting a bank angle of the vehicle body frame; a lean actuator that applies a torque about a rotation axis extending in a front-rear direction of the vehicle to the body frame; A control device that receives a signal from the tilt sensor and controls the lean actuator; A method for calibrating the tilt sensor in a lean vehicle comprising: and executing an independent control for controlling the lean actuator so that a detected bank angle, which is a bank angle of the vehicle body frame detected by the inclination sensor, becomes zero. Detecting an output torque of the lean actuator; determining whether or not the origin of the tilt sensor is shifted based on whether or not the detected bank angle is constant and whether or not an absolute value of the output torque of the lean actuator is equal to or greater than a predetermined threshold value; When it is determined that the tilt sensor has shifted from its origin, the origin position of the tilt sensor is changed; Executing the autonomous control based on the changed origin position; A method for calibrating an inclination sensor of a lean vehicle, the method repeating the determination of the presence or absence of origin deviation, the change of the origin position, and the execution of the self-sustaining control until it is determined that there is no origin deviation.

Images