Overturn determination method and vehicle

Abstract

To provide a fall determination method or the like for improving determination accuracy of a fall.SOLUTION: The overturn determination method includes acquiring a detection result from a first sensor that detects an oscillation amount of an oscillating body that oscillates according to a posture change of a vehicle, acquiring a detection result from one or a plurality of second sensors that detect estimation information for estimating a state of the vehicle separately from the first sensor, determining that the vehicle is overturned when the oscillation amount of the oscillating body satisfies a predetermined overturn condition based on the detection result of the first sensor, and correcting the overturn condition based on the detection result of the second sensor.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a method for determining whether a vehicle has overturned, and to a vehicle. [Background technology]

[0002] Patent Document 1 discloses a vehicle tipping sensor that determines tipping over depending on the swing angle of a pendulum. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-121529 Summary of the Invention [Problem to be solved by the invention]

[0004] The method of determining whether a vehicle has fallen over described in Patent Document 1 may erroneously determine that the vehicle has fallen over even when it is not actually in a falling over state, depending on the road conditions and driving operations.

[0005] Therefore, one aspect of the present disclosure aims to provide a method for determining whether a vehicle has fallen and a vehicle that improves the accuracy of determining whether a vehicle has fallen. [Means for solving the problem]

[0006] A method for determining whether the vehicle has tipped over includes obtaining a detection result from a first sensor that detects the amount of swing of a swinging body that swings in response to a change in the posture of the vehicle; obtaining a detection result from one or more second sensors that are separate from the first sensor and that detect estimated information for estimating the state of the vehicle; determining that the vehicle has tipped over if the amount of swing of the swinging body satisfies a predetermined tipping condition based on the detection result of the first sensor; and correcting the tipping condition based on the detection result of the second sensor. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a side view showing an example of the configuration of a vehicle according to an embodiment as a motorcycle. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of the control circuit and the processing circuit according to the embodiment. [Figure 3] FIG. 3 is a flowchart illustrating an example of a fall determination process by the processing circuit according to the embodiment. [Figure 4] FIG. 4 is a diagram showing an example of the correction process of the second fluctuation threshold value by the processing circuit according to the embodiment. [Figure 5] FIG. 5 is a diagram showing an example of the correction process of the second sway threshold value by the processing circuit according to the embodiment when the vehicle rolls over at a low speed. [Figure 6] FIG. 6 is a diagram showing an example of the correction process of the second sway threshold value by the processing circuit according to the embodiment when the vehicle rolls over at a high speed. [Figure 7] FIG. 7 is a block diagram showing an example of the configuration of the control circuit and processing circuit according to the first modification. [Figure 8] FIG. 8 is a diagram similar to FIG. 4 showing an example of the correction process of the first fluctuation threshold value by the processing circuit. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. The embodiments described below are all comprehensive or specific examples. Among the components in the following embodiments, components that are not recited in an independent claim showing a top concept will be described as optional components. Each figure in the accompanying drawings is a schematic diagram and is not necessarily an exact drawing. In each figure, substantially identical components are assigned the same reference numerals, and duplicated descriptions may be omitted or simplified.

[0009] 1, a vehicle 1 according to an exemplary embodiment will be described. The vehicle 1 includes a drive structure 10 for moving the vehicle 1, a prime mover 20 for transmitting a driving force to drive the drive structure 10, and a control circuit 30 for controlling the operation of the prime mover 20. The vehicle 1 further includes a processing circuit 40 for performing processing to determine whether the vehicle 1 has overturned.

[0010] In this embodiment, the vehicle 1 is a motorcycle. The drive structure 10 of the motorcycle may include three or fewer wheels. Examples of motorcycles include saddle-type vehicles with foot bars on the sides of the seat and scooter-type vehicles with footrests in front of the seat. The vehicle 1 as a motorcycle is a lean vehicle that leans when turning.

[0011] Furthermore, prime mover 20 is an internal combustion engine. An internal combustion engine generates power by repeatedly burning and exploding a mixture of fuel and air in a cylinder. The internal combustion engine converts the reciprocating motion of a piston caused by the combustion and explosion into the rotational motion of a crankshaft, and transmits the rotational power of the crankshaft to the outside. The rotational power transmitted to drive structure 10 may be transmitted to drive wheels among the wheels provided on drive structure 10, and the drive wheels may be driven by the rotational power to move vehicle 1.

[0012] Vehicle 1, which is a motorcycle, has a front wheel 11b and a rear wheel 11a as wheels. The rear wheel 11a is a drive wheel, and the front wheel 11b is a non-drive wheel. Vehicle 1 further includes a body frame 101, a handlebar 102, a steering shaft 103, a pair of left and right front forks 104, a swing arm 105, a rear suspension 106, and a seat 107. The upper part of the front fork 104 is connected to a pair of brackets 114 arranged at a distance in the vertical direction, and the lower part of the front fork 104 rotatably supports the front wheel 11b. The bracket 114 is connected to a steering shaft 103 that supports the handlebar 102. The steering shaft 103 is supported by a head pipe 111, which is part of the body frame 101, so as to be angularly displaceable.

[0013] The swing arm 105 supports the rear wheel 11a, extends in the front-to-rear direction, and is pivotally supported by the body frame 101. The rear suspension 106 is connected to the swing arm 105 and the body frame 101. A seat 107 on which a driver sits is disposed on top of the body frame 101. The prime mover 20 is disposed in a space surrounded by the body frame 101 between the front wheel 11b and the rear wheel 11a, and is fixed to the body frame 101 at multiple portions. The vehicle 1 may include, as the drive structure 10, a transmission 12 and a power transmission member 13 that transmit power generated by the prime mover 20 to the rear wheel 11a. Examples of the power transmission member 13 may include a chain, a belt, and a gear.

[0014] An example of a tipping state of the vehicle 1 as a motorcycle as described above is a state in which the vehicle 1 tilts, causing a part of the body of the vehicle 1 to come into contact with the ground, preventing the vehicle 1 from moving forward with the rear wheel 11a. In this specification and claims, the body of the vehicle 1 may include any part of the vehicle 1 except the front wheel 11b and the rear wheel 11a.

[0015] Here, in this specification, the upward, downward, forward, backward, leftward, and rightward directions are directions based on the vehicle 1 placed upright on the horizontal ground. The upward direction refers to the direction from the ground toward the vehicle 1, and the downward direction refers to the direction from the vehicle 1 toward the ground. The forward direction refers to the forward direction of the vehicle 1. The backward, leftward, and rightward directions each refer to the corresponding directions based on the driver riding on the vehicle 1 standing upright on the ground.

[0016] FIG. 2 is a block diagram showing an example of the configuration of the control circuit 30 and the processing circuit 40 according to the embodiment. As shown in FIG. 2, the vehicle 1 includes a first sensor 50. The vehicle 1 includes a rollover sensor as the first sensor 50. Hereinafter, the "first sensor 50" may be referred to as the "rollover sensor 50." The rollover sensor 50 has a rocking body 51 that rocks in response to a change in the left-right posture of the body of the vehicle 1. The rollover sensor 50 may output a signal indicating that the rocking body 51 rocks by a predetermined amount or more, or may output a signal indicating the amount of rocking of the rocking body 51. For example, when the processing circuit 40 determines, based on the signal provided by the rollover sensor 50, that the rocking body 51 has rocked by a predetermined amount or more due to the rollover of the vehicle 1 continues for a predetermined period of time or more, the processing circuit 40 determines that the vehicle 1 has rolled over.

[0017] The vehicle 1 further includes one or more second sensors 60 having a different structure from the overturn sensor 50. The principle by which the second sensors 60 detect physical quantities is different from the principle by which the overturn sensor 50 detects physical quantities. The second sensors 60 detect a different state of the vehicle 1 from that of the overturn sensor 50. In other words, the second sensors 60 detect estimation information for estimating a different state of the vehicle 1 from that of the overturn sensor 50.

[0018] In this embodiment, a plurality of second sensors 60 are provided, one of which is an inertial force sensor 61 and another of which is a wheel speed sensor 62. The inertial force sensor 61 detects the inertial force acting on the body of the vehicle 1. The wheel speed sensor 62 detects the wheel speed, which is the rotational speed of the front wheels 11b and the rear wheels 11a.

[0019] The processing circuit 40, the control circuit 30, various sensors provided in the vehicle 1, various actuators provided in the vehicle 1, and various electrical devices provided in the vehicle 1 may be interconnected and communicate via a communication network such as a Controller Area Network (CAN) installed in the vehicle 1. The vehicle 1 may include the control circuit 30 and the processing circuit 40 as an electronic control unit (ECU).

[0020] The processing circuit 40 is configured to determine whether the vehicle 1 has overturned or not, based on the detection results of the first sensor 50 and the second sensor 60. When the processing circuit 40 determines that the vehicle 1 has overturned, it is configured to transmit a command for a predetermined operation to be performed in the event of overturning to the control circuit 30. For example, when the processing circuit 40 determines that the vehicle 1 has overturned, it transmits a command to stop the prime mover 20 to the control circuit 30 as a command for the operation to be performed in the event of overturning. This makes it possible to prevent the prime mover 20 from continuing to operate in the overturned state.

[0021] In this embodiment, the processing circuit 40 includes, but is not limited to, a processor 41 and a memory. The processing circuit 40 may include storage within the processing circuit 40 or separately from the processing circuit 40. The memory and storage are collectively referred to as a storage unit 42. A portion of the storage unit 42 may be external to the processing circuit 40 and connected to the processing circuit 40.

[0022] Similarly, in this embodiment, the control circuit 30 includes, but is not limited to, a processor 31 and a memory. The control circuit 30 may include storage within the control circuit 30 or separate from the control circuit 30. The memory and storage are collectively referred to as a storage device 32. A portion of the storage device 32 may be external to the control circuit 30 and connected to the control circuit 30. The control circuit 30 may include some or all of the functions of the processing circuit 40.

[0023] The processor executes functions, methods, or combinations thereof implemented by codes or instructions included in a program stored in storage. Examples of the processor include a central processing unit (CPU), a microprocessing unit (MPU), a graphics processing unit (GPU), a microprocessor, a processor core, a multiprocessor, an application-specific integrated circuit (ASIC), and a field programmable gate array (FPGA). The processor may implement each process described in the present disclosure using a logic circuit formed in an integrated circuit (an integrated circuit (IC) chip, a large-scale integration (LSI)), or a dedicated circuit. These circuits may be implemented using one or more integrated circuits. Multiple processes may be implemented using a single integrated circuit.

[0024] The memory temporarily stores programs loaded from storage and provides a working area for the processor. The memory also temporarily stores various data generated while the processor is executing the programs. Examples of memory include semiconductor memories such as RAM (Random Access Memory) and ROM (Read Only Memory).

[0025] The storage stores programs and various data. Examples of the storage include a hard disk drive (HDD), a solid state drive (SSD), and semiconductor memory such as flash memory.

[0026] Some or all of the functions of the control circuit 30 and the processing circuit 40 may be realized by software functions implemented by a processor and memory, dedicated hardware circuits such as electronic circuits or integrated circuits, or a combination of software functions and hardware circuits.

[0027] The overturn sensor 50 may be any known sensor that can detect the posture of the vehicle 1 in an overturned state. In this embodiment, the overturn sensor 50 detects the amount of lateral swing of the vehicle 1 by detecting the position of the rocking body 51. The rocking body 51 functions as a passive pendulum. That is, the rocking body 51 is stationary when the motion of the vehicle 1 is stopped, and can swing in response to changes in the posture of the vehicle 1 or inertial forces acting on the vehicle 1. The overturn sensor 50 outputs the detection result of the amount of swing of the rocking body 51 that occurs in response to the movement of the vehicle 1 to the processing circuit 40.

[0028] For example, when the body of the vehicle 1 swings left and right, the rocking body 51 physically swings, changing the relationship between the rocking body 51 and the vertical direction. The tip-over sensor 50 may have a structure that allows the rocking body 51 to swing left and right of the vehicle 1. As a result, the amount of rocking of the rocking body 51 corresponds to the amount of tilt of the vehicle 1 in the left and right direction. The tip-over sensor 50 may detect the amount of tilt of the vehicle 1 in the left and right direction based on the amount of rocking of the rocking body 51.

[0029] For example, the oscillator 51 may have a structure that oscillates around an oscillation axis. Specifically, the oscillator 51 may have a pendulum structure in which the oscillator 51 is suspended from an oscillation axis, or may have a structure in which the oscillation axis passes through the oscillator 51. In the latter case, the oscillation axis may pass through a position offset from the center of gravity of the oscillator 51.

[0030] For example, the tip-over sensor 50 may be configured to change its electrical output value when the oscillator 51 swings beyond a predetermined swing amount and comes into contact with a wall. Alternatively, the tip-over sensor 50 may be configured to detect a change in magnetic field caused by the swing of the magnetic oscillator 51 using a Hall IC element.

[0031] Depending on the predetermined driving conditions of the vehicle 1, the overturn sensor 50 may erroneously detect a non-overturned state as an overturned state. For example, if the rocking body 51 undesirably rocks from side to side due to up and down vibrations that occur when the vehicle 1 travels on an uneven road surface, the processing circuit 40 may determine that the vehicle 1 is in an overturned state if it determines whether the vehicle 1 has overturned based solely on the output signal from the overturn sensor 50.

[0032] The one or more second sensors 60 detect inferred information for estimating the state of the vehicle 1 and output the detection results to the processing circuit 40, the control circuit 30, or both. The state of the vehicle 1 may be a state of the vehicle 1 that is correlated with the vehicle 1 tipping over.

[0033] For example, the state of the vehicle 1 may be that the vehicle 1 is in an upright or non-upright state while moving. If the vehicle 1 is moving in an upright state, it is highly likely that the vehicle 1 is not tipping over, and therefore, the state of the vehicle 1 as described above is correlated with the vehicle 1 tipping over.

[0034] When the vehicle 1 moves in an upright position, the force acting on the vehicle 1 in the left-right direction decreases as the posture of the vehicle 1 approaches the upright posture.

[0035] In vehicle 1 as a motorcycle, even if the outer diameter of front wheel 11b is the same as that of rear wheel 11a, the radius of curvature of the wheel cross section, i.e., the radius of curvature of the contact patch, of rear wheel 11a is larger than that of front wheel 11b. For example, as the amount of left-right lean of vehicle 1 increases, the diameter of rear wheel 11a becomes larger than the diameter of front wheel 11b, and the difference in wheel speed between front wheel 11b and rear wheel 11a increases.

[0036] Thus, the state of the vehicle 1 may be a state related to the behavior of the vehicle 1 while it is moving, such as the attitude of the vehicle 1 or the forces acting on the vehicle 1. Therefore, the one or more second sensors 60 may include a cruise control sensor used to control the behavior of the vehicle 1 while it is moving.

[0037] Inertial force sensor 61, which is one of second sensors 60, outputs the detection result to processing circuit 40 as estimated information. Inertial force sensor 61 is one of the sensors for driving control. Inertial force sensor 61 includes acceleration sensor 611 and may further include gyro sensor 612. Acceleration sensor 611 detects forces acting in two or three detection axis directions that intersect with each other. The detection axes may be orthogonal to each other. Although not limited thereto, in this embodiment, acceleration sensor 611 detects at least forces acting in the detection axis direction in the left-right direction of vehicle 1 and forces acting in the detection axis direction in the up-down direction of vehicle 1. Gyro sensor 612 detects angular velocity or angular acceleration around two or three detection axes that intersect with each other. The detection axes may be orthogonal to each other or may be the same as the detection axes of acceleration sensor 611.

[0038] In this way, inertial force sensor 61 detects inertial forces or gravity acting in the directions in which a plurality of predetermined detection axes extend, and inertial forces acting in the directions of rotation about a plurality of predetermined detection axes. For example, inertial force sensor 61 may include a vibrator and a stator that actively vibrate at a constant cycle regardless of the movement of vehicle 1. Inertial force sensor 61 may output the movement speed and angular velocity of the vibrator caused by the action of inertial force or gravity as a change in electrostatic capacitance between the vibrator-side electrode and the stator-side electrode.

[0039] The processing circuit 40 estimates the likelihood that the vehicle 1 is continuing to move due to the rotation of the rear wheel 11a, which is the drive wheel, based on the detection result of the second sensor 60. When the vehicle 1 is continuing to move due to the rotation of the rear wheel 11a, there is a high likelihood that the vehicle 1 is not tipping over. Therefore, the state in which the vehicle 1 is continuing to move due to the rotation of the rear wheel 11a correlates with the state in which the vehicle 1 is not tipping over. Therefore, the processing circuit 40 can estimate the likelihood that the vehicle 1 is continuing to move due to the rotation of the rear wheel 11a by estimating the likelihood that the vehicle 1 is not tipping over.

[0040] Processing circuit 40 may estimate the likelihood that vehicle 1 will not tip over based on the detection results of inertial force sensor 61. In the present embodiment, processing circuit 40 detects forces acting in the left-right direction on vehicle 1 based on the detection results of inertial force sensor 61, and estimates the likelihood that vehicle 1 will not tip over based on the forces acting in the left-right direction. The forces acting in the left-right direction on vehicle 1 are forces that act in the left-right and horizontal directions of vehicle 1.

[0041] Processing circuit 40 may estimate the attitude of vehicle 1 based on the detection results of the angular velocity or angular acceleration about each detection axis of inertial force sensor 61. Processing circuit 40 may estimate the force acting in the left-right direction on vehicle 1 based on the attitude of vehicle 1 and the detection results of the acceleration in each detection axis direction of inertial force sensor 61. Processing circuit 40 may detect a difference in the attitude of vehicle 1 with respect to the upright attitude of vehicle 1.

[0042] The processing circuit 40 may estimate the likelihood that the vehicle 1 will not tip over, depending on the magnitude of the force acting in the left-right direction on the vehicle 1. For example, the force acting in the left-right direction on the vehicle 1 is zero when the vehicle 1 is not turning, in other words, when no centrifugal force is being generated on the vehicle 1. Therefore, if the force acting in the left-right direction is zero while the vehicle 1 continues traveling, it can be estimated that there is a high likelihood that the vehicle 1 will not tip over.

[0043] The processing circuit 40 may estimate that there is a high possibility that the vehicle 1 is not overturning when the magnitude of the force acting in the left-right direction is equal to or less than a first threshold value T1 that is close to 0. The first threshold value T1 is greater than 0. The processing circuit 40 may estimate that there is a high possibility that the vehicle 1 is not overturning when the above state continues for an estimation period ta that is a predetermined period.

[0044] The processing circuit 40 may estimate a determination value C1 indicating the likelihood that the vehicle 1 will not roll over, depending on the magnitude of the force acting in the left-right direction. The greater the likelihood that the vehicle 1 will not roll over while the vehicle 1 continues traveling, the larger the determination value C1 may be. In this embodiment, the determination value C1 takes a positive value, indicating that the vehicle 1 is likely to not roll over. The determination value C1 may take a negative value, indicating that the vehicle 1 is likely to have rolled over. The determination value C1 may express the likelihood that the vehicle 1 will not roll over as a percentage or a ratio. The processing circuit 40 may estimate whether the vehicle 1 will not roll over based on whether the determination value C1 exceeds a predetermined threshold.

[0045] The processing circuit 40 may determine the determination value C1 to be a maximum value, such as 100%, when the absolute value of the force acting in the left-right direction is 0 or less than or equal to a first threshold value T1. The processing circuit 40 may determine the determination value C1 to be a maximum value when the above state continues for a predetermined estimation period ta. The processing circuit 40 may determine the determination value C1 to be smaller as the absolute value of the force acting in the left-right direction increases. The processing circuit 40 may correct the determination value C1 in accordance with an integrated value of the force acting in the left-right direction, past trends, changes over time, or a combination of two or more of these. The processing circuit 40 may determine that the vehicle 1 has not overturned when the determination value C1 exceeds a predetermined threshold.

[0046] In this embodiment, the wheel speed sensor 62 includes a driven wheel speed sensor 621 that detects the rotation speed of the front wheels 11b, which are non-driven wheels of the vehicle 1, and a drive wheel speed sensor 622 that detects the rotation speed of the rear wheels 11a, which are driven wheels of the vehicle 1. Examples of the driven wheel speed sensor 621 and the drive wheel speed sensor 622 may include an electromagnetic pickup type rotation sensor, an anisotropic-magneto-resistive (AMR) rotation sensor, a Hall IC rotation sensor, and a mechanical, optical, magnetic, or electromagnetic induction encoder. The wheel speed sensor 62 outputs the detection result as estimated information to the processing circuit 40. The wheel speed sensor 62 is one of the sensors for driving control.

[0047] The processing circuit 40 may estimate the likelihood that the vehicle 1 will not tip over based on the detection result of the wheel speed sensor 62. The processing circuit 40 may detect the front wheel traveling speed, which is the traveling speed of the vehicle 1 driven by the front wheels 11b, based on the detection result of the driven wheel speed sensor 621. The processing circuit 40 may detect the rear wheel traveling speed, which is the traveling speed of the vehicle 1 driven by the rear wheels 11a, based on the detection result of the drive wheel speed sensor 622. The control circuit 30 can control the output of the prime mover 20 to output an appropriate driving force in accordance with the traveling speed of the vehicle 1 based on the detection result of the driven wheel speed sensor 621. In this embodiment, the traveling speed of the vehicle 1 corresponds to the front wheel traveling speed.

[0048] The processing circuit 40 may estimate the likelihood that the vehicle 1 will not tip over based on the detection results of the driven wheel speed sensor 621 and the drive wheel speed sensor 622. In this case, the processing circuit 40 detects the difference in rotational speed between the front wheels 11b and the rear wheels 11a, or the difference in traveling speed between the front wheel traveling speed and the rear wheel traveling speed, based on the above detection results. Specifically, the processing circuit 40 may calculate the slip ratio using the front wheel rotational speed and the rear wheel rotational speed, or the front wheel traveling speed and the rear wheel traveling speed. The slip ratio may be expressed as "(front wheel traveling speed - rear wheel traveling speed) / rear wheel traveling speed." In particular, when the outer diameter of the front wheel 11b and the outer diameter of the rear wheel 11a are the same, the slip ratio may be expressed as "(front wheel rotational speed - rear wheel rotational speed) / rear wheel rotational speed."

[0049] For example, when the difference in rotational speed or travel speed between the front and rear wheels is small, in other words, when the slip ratio is small, there is a high possibility that the vehicle 1 is traveling without tipping over. Hereinafter, the "difference in rotational speed between the front and rear wheels" and the "difference in travel speed between the front and rear wheels" may be collectively referred to as the "wheel speed difference." The processing circuit 40 estimates that the smaller the wheel speed difference or slip ratio, the higher the possibility that the vehicle 1 is not tipping over.

[0050] When using the slip ratio, the slip ratio increases as the rotational speed of the rear wheels 11a, which are the drive wheels, decreases, even if the wheel speed difference is small, and therefore the threshold value for determining that the vehicle 1 has not rolled over may be corrected in accordance with the traveling speed or the rotational speed of the drive wheels. Specifically, it is preferable to correct the slip ratio so that the smaller the slip ratio, the higher the possibility that the vehicle 1 has not rolled over, while the lower the traveling speed or the rotational speed of the drive wheels, the lower the possibility that the vehicle 1 has not rolled over.

[0051] The processing circuit 40 may estimate that there is a high possibility that the vehicle 1 is not overturning when the magnitude of the slip ratio is 0 or less than a second threshold value T2 and the traveling speed of the vehicle 1 is greater than a third threshold value T3. The second threshold value T2 may be a value greater than 0 and close to 0. The processing circuit 40 may estimate that there is a high possibility that the vehicle 1 is not overturning when the above state continues for an estimation period ta.

[0052] The processing circuit 40 may estimate a determination value CA indicating the likelihood that the vehicle 1 will not roll over, depending on the slip ratio and traveling speed of the vehicle 1. In the present embodiment, the determination value CA is expressed using a determination value C2 related to the slip ratio and a determination value C3 related to the traveling speed, but is not limited thereto. The determination values ​​CA, C2, and C3 may express the likelihood that the vehicle 1 will not roll over as a percentage or a ratio. In the present embodiment, the determination values ​​C2 and C3 take positive values ​​indicating that the vehicle 1 is likely not to roll over, but may also take negative values ​​indicating that the vehicle 1 is likely to have rolled over. The processing circuit 40 may estimate whether the vehicle 1 will not roll over based on whether the determination value CA exceeds a predetermined threshold.

[0053] When the absolute value of the slip ratio is 0 or equal to or less than the second threshold value T2, the processing circuit 40 may set the judgment value C2 to a maximum value such as 100%. When the above state continues over the estimation period ta, the processing circuit 40 may set the judgment value C2 to a maximum value. The processing circuit 40 may set the judgment value C2 so that it decreases as the absolute value of the slip ratio increases. The processing circuit 40 may correct the slip ratio judgment value in accordance with the slip ratio integral value, past trend, time change, or a combination of two or more of these, etc.

[0054] When the traveling speed is equal to or greater than the third threshold T3, the processing circuit 40 may set the judgment value C3 to a maximum value, such as 100%. When the above state continues for the estimation period ta, the processing circuit 40 may set the judgment value C3 to a maximum value. The processing circuit 40 may set the judgment value C3 to be smaller as the traveling speed decreases from the third threshold T3. The processing circuit 40 may correct the judgment value C3 according to the integrated value of the traveling speed, past trends, changes over time, or a combination of two or more of these, or the like.

[0055] The processing circuit 40 may determine that the vehicle 1 is in a non-overturned state when the determination value CA, which includes the combination of the determination values ​​C2 and C3, exceeds a predetermined threshold. For example, the determination values ​​C2 and C3 may be combined by an operation such as addition, multiplication, or division.

[0056] In this embodiment, the processing circuit 40 estimates the likelihood that the vehicle 1 will not roll over using the magnitude of the inertial force acting in the left-right direction on the vehicle 1, the slip ratio of the vehicle 1, and the traveling speed of the vehicle 1. The processing circuit 40 estimates whether or not there is a high likelihood that the vehicle 1 will not roll over using the result of comparing the absolute value of the inertial force in the left-right direction with the first threshold value T1, the result of comparing the absolute value of the slip ratio with the second threshold value T2, and the result of comparing the traveling speed with the third threshold value.

[0057] Specifically, the processing circuit 40 determines a judgment value C1 based on the inertial force in the lateral direction, a judgment value C2 based on the slip ratio, and a judgment value C3 based on the traveling speed, and determines whether the vehicle 1 has not overturned based on a judgment value CB that combines the three judgment values. The processing circuit 40 may combine the three judgment values ​​using an operation such as addition, multiplication, or division.

[0058] The processing circuit 40 may determine the judgment value CB to be a maximum value, such as 100%, when the absolute value of the inertial force in the lateral direction is equal to or less than a first threshold T1, the absolute value of the slip ratio is equal to or less than a second threshold T2, and the traveling speed is equal to or greater than a third threshold. The processing circuit 40 may determine the judgment value CB so that it decreases as the absolute value of the inertial force in the lateral direction increases from the first threshold T1, as the absolute value of the slip ratio increases from the second threshold T2, or as the traveling speed decreases from the third threshold. The processing circuit 40 may determine the judgment value CB using the inertial force in the lateral direction, the slip ratio, and the traveling speed that continue over the estimation period ta.

[0059] The operation of the processing circuit 40, which determines whether the vehicle 1 has overturned using the detection results of the overturn sensor 50 and one or more second sensors 60, will now be described in detail. The processing circuit 40 is configured to determine that the vehicle 1 has overturned when the amount of rocking of the rocking body 51 satisfies a predetermined overturn condition based on the detection result of the overturn sensor 50. The processing circuit 40 may determine whether the vehicle 1 has overturned using the overturn condition for each predetermined determination period tb. The overturn condition is that the amount of rocking of the rocking body 51 continues to be equal to or greater than the first rocking threshold Toa for a period equal to or greater than the second rocking threshold Tob. As the initial overturn condition, an initial setting value Toa0 of the first rocking threshold Toa and an initial setting value Tob0 of the second rocking threshold Tob are generated in advance and stored in the memory 42.

[0060] The processing circuit 40 is configured to correct the rollover condition based on the detection results of the one or more second sensors 60. The processing circuit 40 corrects the rollover condition based on the likelihood that the vehicle 1 will not roll over, which is estimated based on the detection results of the one or more second sensors 60.

[0061] The processing circuit 40 may determine whether to correct the fall conditions for each predetermined correction period tc. The processing circuit 40 may receive detection results from one or more second sensors 60 for each predetermined detection period td. The correction period tc may be the same as or different from the determination period tb. The correction period tc is preferably equal to or shorter than the determination period tb, but may be longer than the determination period tb. The detection period td is shorter than the determination period tb. The correction period tc may be the same as or different from the detection period td. The correction period tc is preferably equal to or longer than the detection period td. The estimation period ta may be the same as the determination period tb, the correction period tc, or the detection period td, or may be different from any of them. The estimation period ta may be set according to the type of the second sensor 60.

[0062] Examples of the detection period td may include a period of 10 milliseconds or less, a period between 10 and 20 milliseconds, and a period of tens of milliseconds. Examples of the determination period tb may include a period between 100 and 200 milliseconds, a period of hundreds of milliseconds, a period between 1 and 2 seconds, and a period of several seconds. Examples of the correction period tc may include a period of 10 milliseconds or less, a period between 10 and 20 milliseconds, a period of tens of milliseconds, a period between 100 and 200 milliseconds, a period of hundreds of milliseconds, a period between 1 and 2 seconds, and a period of several seconds.

[0063] When the processing circuit 40 estimates that there is a high possibility that the vehicle 1 is not overturning, that is, that there is a high possibility that the vehicle 1 is continuing to move due to the rotation of the rear wheels 11a, which are the drive wheels, the processing circuit 40 corrects the overturning conditions so that it is less likely to determine that the vehicle 1 has overturned, compared to when the possibility is lower. Although not limited thereto, in this embodiment, the processing circuit 40 corrects the second sway threshold Tob to be larger. Note that the processing circuit 40 may also correct the first sway threshold Toa to be larger.

[0064] When the processing circuit 40 estimates that the vehicle 1 is unlikely to be in a non-overturned state, that is, that the vehicle 1 is unlikely to be continuing to move due to the rotation of the rear wheel 11a, the processing circuit 40 may correct the overturn condition so that it is more likely to determine that the vehicle 1 has overturned than when the probability is higher. In this case, the processing circuit 40 corrects the second sway threshold Tob to be smaller in this embodiment, but may also correct the first sway threshold Toa to be smaller.

[0065] For each correction period tc, the processing circuit 40 determines whether to correct the overturn condition using the detection results of one or more second sensors 60 acquired within the correction period tc. For example, the processing circuit 40 may determine to correct the overturn condition based on the estimation result of the likelihood that the vehicle 1 will not overturn during the correction period tc. The processing circuit 40 may also determine to correct the overturn condition when the determination value fluctuates during the correction period tc.

[0066] The processing circuit 40 determines whether the detection results of one or more second sensors 60 fall within an abnormal range that exceeds a predetermined normal range. When the processing circuit 40 determines that the detection results of one or more second sensors 60 fall within the abnormal range, it invalidates the corrections made to the tipping conditions and determines and fixes the tipping conditions to the initial setting values ​​of the tipping conditions stored in the memory 42. Note that when the processing circuit 40 determines that the detection results of one or more second sensors 60 fall within the abnormal range, it may not make further corrections to the tipping conditions and may fix the tipping conditions to the current tipping conditions.

[0067] For the second sensor 60 that has detected an abnormal range, the processing circuit 40 determines whether the detection result of the second sensor 60 has continued to fall within the normal range for a predetermined release period te. If the processing circuit 40 determines that the detection result of the second sensor 60 has continued to fall within the normal range for at least the release period te, it releases the fixation of the tip-over condition and allows correction of the tip-over condition.

[0068] The correction of the rollover condition will now be described in detail. The processing circuit 40 estimates the likelihood that the vehicle 1 will not roll over for each of the one or more second sensors 60 based on the detection results of the second sensors 60. The processing circuit 40 corrects the sway threshold of the rollover condition by increasing or decreasing it, by reflecting the estimation results for each of the one or more second sensors 60.

[0069] Although not limited thereto, in this embodiment, the processing circuit 40 corrects the second sway threshold Tob to increase or decrease it. Specifically, the processing circuit 40 sets the second sway threshold Tob by applying a judgment value indicating the likelihood that the vehicle 1 will not roll over to an initial setting value Tob0 of the second sway threshold Tob. The processing circuit 40 uses the judgment value of an estimation element, which is an element for estimating the likelihood that the vehicle 1 will not roll over. Examples of the estimation element may include the force acting on the vehicle 1, the rotational speed of the front and rear wheels of the vehicle 1, the slip ratio of the vehicle 1, the traveling speed of the vehicle 1, the expansion / contraction state of the suspension of the vehicle 1, and the tire air pressure of the vehicle 1. In this embodiment, the estimation element includes the force acting on the vehicle 1, the slip ratio of the vehicle 1, and the traveling speed of the vehicle 1.

[0070] The processing circuit 40 corrects the second fluctuation threshold value Tob by varying the determination value based on the detection results of one or more second sensors 60. In this embodiment, the processing circuit 40 corrects the second fluctuation threshold value Tob based on the determination value so as to increase the initial setting value Tob0 of the second fluctuation threshold value Tob.

[0071] For example, the second sway threshold Tob can be defined by the relational expression Tob=Tob0×(1+f(Ck)) using the initial setting value Tob0 of the second sway threshold and the judgment value Ck corresponding to the estimated element. The judgment value Ck represents the percentage of the high probability that the vehicle 1 will not roll over as a value between 0 and 1. The judgment value Ck represents the maximum value of 100% of the high probability that the vehicle 1 will not roll over as "1", and the minimum value of 0% of this percentage as "0". k is a subscript representing the estimated element and is represented by a natural number from 1 to n, where "n" is a natural number greater than or equal to 1.

[0072] f(Ck) is a function whose elements are the judgment values ​​C1 to Cn. An example of f(Ck) is f(Ck)=C1+C2+···+Cn. In this example, the multiple judgment values ​​Ck are used as additive elements to be added to the reference value "1" in the above relational expression, but this is not limited to this. f(Ck) may include subtraction, multiplication, or division of two or more of the multiple judgment values ​​Ck. For example, a certain judgment value Ck1 of the multiple judgment values ​​Ck may be used as a subtraction element, multiplication element, or division element for another judgment value Ck2. The judgment values ​​Ck1 and Ck2 may be judgment values ​​of estimation elements related to each other. Although not limited to this, in this embodiment, the judgment value Ck includes the judgment values ​​C1, C2, and C3.

[0073] The determination value C1 relating to the inertial force in the lateral direction acting on the vehicle 1 can be used as an additive element in the above relational expression for the second sway threshold value Tob.

[0074] The determination value C1 may be set to a predetermined value greater than 0, such as "1", when the inertial force in the left-right direction is 0, and may be set to "0" when the inertial force in the left-right direction is greater than 0.

[0075] The judgment value C1 may be set to a value greater than 0, such as "1", when the absolute value of the left-right inertial force is less than or equal to the first threshold value T1, and may be set to "0" when the absolute value of the left-right inertial force is greater than the first threshold value T1.

[0076] The judgment value C1 may be set to gradually decrease as the absolute value of the inertial force in the left-right direction increases. For example, one or more judgment values ​​C1 may be set in a range exceeding the first threshold T1. The judgment value C1 may be set to "1" for a range greater than or equal to 0 and less than or equal to the first threshold T1, set to "0" for a range greater than the fourth threshold T4, and set to a predetermined value greater than 0 and less than 1 for a range greater than the first threshold T1 and less than or equal to the fourth threshold T4. The fourth threshold T4 is greater than the first threshold T1. The processing circuit 40 compares the three ranges with the absolute value of the inertial force in the left-right direction to determine a judgment value corresponding to the absolute value of the inertial force in the left-right direction from among the three judgment values ​​C1. Alternatively or in addition to the above, one or more judgment values ​​C1 may be set in a range greater than or equal to 0 and less than or equal to the first threshold T1. The processing circuit 40 may determine a judgment value corresponding to the absolute value of the inertial force in the left-right direction from among four or more judgment values ​​C1 corresponding to four or more ranges.

[0077] The judgment value C2 regarding the slip ratio of the vehicle 1 can be used as an additive element in the above relational expression for the second sway threshold value Tob.

[0078] The judgment value C2 may be set to a predetermined value greater than 0, such as "1", when the slip ratio is 0, and may be set to "0" when the absolute value of the slip ratio is greater than 0.

[0079] The judgment value C2 may be set to a predetermined value greater than 0, such as "1", when the absolute value of the slip ratio is less than or equal to the second threshold value T2, and may be set to "0" when the absolute value of the slip ratio is greater than the second threshold value T2.

[0080] The judgment value C2 may be set to gradually decrease as the absolute value of the slip ratio increases. For example, one or more judgment values ​​C2 may be set in a range exceeding the second threshold T2. The judgment value C2 may be set to "1" for a range greater than or equal to 0 and less than or equal to the second threshold T2, set to "0" for a range greater than the fifth threshold T5, and set to a predetermined value greater than 0 and less than 1 for a range greater than the second threshold T2 and less than or equal to the fifth threshold T5. The fifth threshold T5 is greater than the second threshold T2. Alternatively or in addition to the above, one or more judgment values ​​C2 may be set in a range greater than or equal to 0 and less than or equal to the second threshold T2. The processing circuit 40 may determine a judgment value corresponding to the absolute value of the slip ratio from among multiple judgment values ​​C2 corresponding to each of multiple ranges.

[0081] The judgment value C3 relating to the traveling speed of the vehicle 1 is used as a multiplication element by which the judgment value C2 is multiplied in the above relational expression for the second sway threshold value Tob, but may also be used as another calculation element.

[0082] The judgment value C3 may be set to "0" when the running speed or rotation speed, which is the front wheel travel speed of the front wheel 11b, is less than the third threshold value T3, and may be set to a predetermined value greater than 0, such as "1", when the running speed or rotation speed of the front wheel 11b is greater than or equal to the third threshold value T3.

[0083] The determination value C3 may be set to increase in stages as the traveling speed or the rotation speed of the front wheels 11b increases.

[0084] For example, one or more judgment values ​​C3 may be set in a range below the third threshold T3. The judgment value C3 may be set to "0" for a range greater than or equal to 0 and less than the sixth threshold T6, set to "1" for a range greater than or equal to the third threshold T3, and set to a predetermined value greater than 0 and less than 1 for a range greater than the sixth threshold T6 and less than the third threshold T3. The sixth threshold T6 is greater than 0 and less than the third threshold T3. Alternatively or in addition to the above, one or more judgment values ​​C3 may be set in a range greater than the third threshold T3. The processing circuit 40 may determine a judgment value corresponding to the traveling speed or the rotational speed of the front wheels 11b from among a plurality of judgment values ​​C4 corresponding to each of a plurality of ranges.

[0085] Therefore, in this embodiment, f(Ck) is defined as f(Ck)=C1+C2×C3, and the second sway threshold Tob can be defined as Tob=Tob0×(1+C1+C2×C3). According to the relational expression Tob=Tob0×(1+C1+C2×C3), when the judgment value Ck is greater than 0, the second sway threshold Tob is corrected by the judgment value Ck so as to be greater than the initial setting value Tob0. When the judgment value Ck is greater than 0 and there is a possibility that the vehicle 1 has not rolled over, the second sway threshold Tob is corrected so as to be greater than the initial setting value Tob0, making it more difficult for the rollover condition to be satisfied.

[0086] The conditions under which the overturn sensor 50 can accurately detect a rollover of the vehicle 1 and the conditions under which the second sensor 60 can accurately detect a high possibility that the vehicle 1 has rolled over may differ. For this reason, the processing circuit 40 improves the accuracy of detecting that the vehicle 1 has not rolled over or that the vehicle 1 has rolled over in a situation where the overturn sensor 50 would erroneously detect that the vehicle 1 has not rolled over or that the vehicle 1 has rolled over by complementarily correcting the sway threshold using the detection result of the second sensor 60. For example, the detection accuracy of the overturn sensor 50 may decrease when low-frequency vibrations occur in the vehicle 1 due to the motor 20 or the like. Because the effect of these vibrations on the detection result of the second sensor 60 differs from the effect of these vibrations on the detection result of the overturn sensor 50, the processing circuit 40 reduces erroneous detection of that the vehicle 1 has not rolled over or that the vehicle 1 has rolled over by using the detection result of the second sensor 60.

[0087] In this embodiment, the second sensor 60 is not installed in the vehicle 1 specifically for determining whether the vehicle 1 has rolled over, but can be installed in the vehicle 1 in advance, regardless of whether it is necessary to determine whether the vehicle 1 has rolled over. The processing circuit 40 uses an existing sensor in the vehicle 1 as the second sensor 60 to determine whether the vehicle 1 has rolled over. This reduces the cost of the vehicle 1.

[0088] The operation of the processing circuit 40 according to the embodiment to determine whether the vehicle 1 has rolled over will be described. Fig. 3 is a flowchart showing an example of the rollover determination process of the processing circuit 40 according to the embodiment. Fig. 3 shows an example in which the timing and length of the determination period tb are the same as the timing and length of the correction period tc.

[0089] As shown in FIG. 3, in step S101, the processing circuit 40 starts timing the correction period tc.

[0090] In step S102, the processing circuit 40 acquires detection results from the fall sensor 50 and one or more second sensors 60, which are sensors for driving control.

[0091] In step S103, the processing circuit 40 determines whether the measured time has reached the correction period tc. If the measured time has not reached the correction period tc (No in step S103), the processing circuit 40 returns to step S102, and if the measured time has reached the correction period tc (Yes in step S103), the processing circuit 40 proceeds to step S104.

[0092] In step S104, the processing circuit 40 determines whether the second fluctuation threshold Tob is correctable. If the second fluctuation threshold Tob is not correctable (Yes in step S104), the processing circuit 40 proceeds to step S105, and if the second fluctuation threshold Tob is correctable (No in step S104), the processing circuit 40 proceeds to step S111.

[0093] The second sway threshold Tob cannot be corrected when the detection results of the cruise control sensor 60 indicate an abnormal range. In such a case, the processing circuit 40 disables the correction made to the second sway threshold Tob, fixes the second sway threshold Tob to the initial setting value Tob0, and disables correction from the initial setting value Tob0. After the second sway threshold Tob is fixed, if the detection results of the cruise control sensor 60 that indicated an abnormal range continue to indicate a normal range for a period longer than the release period te, the processing circuit 40 enables correction of the second sway threshold Tob from the initial setting value Tob0. The processing circuit 40 may perform the process of enabling or disabling correction in parallel with the process of determining whether the vehicle 1 has rolled over, using an algorithm separate from the algorithm for determining whether the vehicle 1 has rolled over.

[0094] In step S105, the processing circuit 40 determines the judgment value Ck of the second sway threshold Tob using the detection results of one or more driving control sensors 60. That is, the processing circuit 40 calculates the judgment values ​​of the estimation elements using the detection results of one or more driving control sensors 60. The processing circuit 40 may store in advance in the memory 42 a series of data including the values ​​of various estimation elements associated with the judgment values.

[0095] In step S106, the processing circuit 40 determines the second fluctuation threshold value Tob using the determined judgment value. If the judgment value does not change before and after the determination, the second fluctuation threshold value Tob does not change before and after the determination, and if the judgment value changes before and after the determination, the second fluctuation threshold value Tob changes before and after the determination and is corrected.

[0096] In step S107, the processing circuit 40 determines whether the amount of oscillation of the oscillator 51 is equal to or greater than the first oscillation threshold Toa. If the amount of oscillation is equal to or greater than the first oscillation threshold Toa (Yes in step S107), the processing circuit 40 proceeds to step S108, and if the amount of oscillation is less than the first oscillation threshold Toa (No in step S107), the processing circuit 40 returns to step S101. If the amount of oscillation is less than the first oscillation threshold Toa, the processing circuit 40 resets the count, which is the number of times a determination period tb, described later, has elapsed, to 0.

[0097] In step S108, the processing circuit 40 counts the number of times the determination period tb has elapsed. The processing circuit 40 increments the count of the number of times the determination period tb has elapsed up to this point by one.

[0098] In step S109, the processing circuit 40 determines whether the elapsed time is equal to or greater than the determined second fluctuation threshold value Tob. If the elapsed time is equal to or greater than the determined second fluctuation threshold value Tob (Yes in step S109), the processing circuit 40 proceeds to step S110, and if the elapsed time is less than the determined second fluctuation threshold value Tob (No in step S109), the processing circuit 40 returns to step S101.

[0099] In step S110, the processing circuit 40 determines that the vehicle 1 has overturned.

[0100] In step S111, the processing circuit 40 determines whether the amount of oscillation of the oscillator 51 is equal to or greater than the first oscillation threshold Toa. If the amount of oscillation is equal to or greater than the first oscillation threshold Toa (Yes in step S111), the processing circuit 40 proceeds to step S112, and if the amount of oscillation is less than the first oscillation threshold Toa (No in step S111), the processing circuit 40 returns to step S101. If the amount of oscillation is less than the first oscillation threshold Toa, the processing circuit 40 resets the count number of the determination period tb to 0.

[0101] In step S112, the processing circuit 40 counts the number of times the determination period tb has elapsed. The processing circuit 40 increments the count of the number of times the determination period tb has elapsed up to this point by one.

[0102] In step S113, the processing circuit 40 determines whether the elapsed time is equal to or greater than the initial setting value Tob0 as the second fluctuation threshold value Tob. The elapsed time is obtained by multiplying the determination period tb by the count number of the determination period tb. If the elapsed time is equal to or greater than the initial setting value Tob0 (Yes in step S113), the processing circuit 40 proceeds to step S110, and if the elapsed time is less than the initial setting value Tob0 (No in step S113), the processing circuit 40 returns to step S101.

[0103] According to steps S101 to S113, the processing circuit 40 determines whether or not to correct the second sway threshold Tob and corrects it for each correction period tc, regardless of whether the amount of sway detected by the overturn sensor 50 is equal to or greater than the first sway threshold Toa. When the amount of sway detected by the overturn sensor 50 is equal to or greater than the first sway threshold Toa, the processing circuit 40 can determine whether the vehicle 1 has overturned using the corrected second sway threshold Tob. The processing circuit 40 can accurately determine whether the vehicle 1 has overturned using the second sway threshold Tob while correcting the second sway threshold Tob according to the state of the vehicle 1. Furthermore, when there is an abnormality in the detection result of the cruise control sensor 60, the processing circuit 40 uses the initial setting value Tob0 without correcting the second sway threshold Tob, thereby reducing erroneous determination of whether the vehicle 1 has overturned.

[0104] An example of processing related to determining whether the vehicle 1 has rolled over by the processing circuit 40 according to the embodiment will be described. FIG. 4 is a diagram illustrating an example of processing for correcting the second sway threshold Tob by the processing circuit 40 according to the embodiment. FIG. 4 illustrates a case in which the vehicle 1 travels over an uneven road surface without rolling over. As shown in FIG. 4, because the vehicle 1 travels over an uneven road surface, the rollover sensor 50 detects a sway amount whose absolute value is equal to or greater than the first sway threshold Toa at elapsed time t11. Before and after elapsed time t11, the absolute value of the lateral inertial force is equal to or less than the first threshold T1, the rotational speed of the front wheel 11b is equal to or greater than the third threshold T3, and the absolute value of the slip ratio is equal to or less than the second threshold T2. Therefore, before elapsed time t11, the processing circuit 40 corrects the second sway threshold Tob to a value Tob1, which is greater than the initial setting value Tob0, and maintains the value at that value.

[0105] During the period (t12-t11) from elapsed time t11 to elapsed time t12, the absolute value of the amount of sway is equal to or greater than the first sway threshold Toa. The initial setting value Tob0 of the second sway threshold Tob is less than the period (t12-t11), but the corrected second sway threshold Tob1 is greater than the period (t12-t11), so the processing circuit 40 determines that the vehicle 1 has not overturned. Therefore, the processing circuit 40 can determine with high accuracy whether the vehicle 1 has overturned, even in cases where the processing circuit 40 would erroneously determine that the vehicle 1 has overturned based solely on the amount of sway of the vehicle 1.

[0106] FIG. 5 is a diagram showing an example of the process of correcting the second sway threshold Tob by the processing circuit 40 according to this embodiment when the vehicle 1 rolls over at a low speed. The low speed range is preferably a speed range of 30 km / h or less, and more preferably a speed range of 20 km / h or less. Depending on the circumstances, the vehicle 1 may roll over if the rear wheel 11a slides on the road surface. As shown in FIG. 5, the vehicle 1 experiences a phenomenon called slipdown, in which the rear wheel 11a slides on the road surface, at elapsed time t22, and then falls into a rollover state in which the body of the vehicle 1 touches the ground at elapsed time t23.

[0107] Up to elapsed time t21, which is before elapsed time t22, the absolute value of the lateral inertial force is equal to or less than the first threshold value T1, the rotational speed of the front wheel 11b is equal to or greater than the third threshold value T3, and the absolute value of the slip ratio is equal to or less than the second threshold value T2. Therefore, the processing circuit 40 sets the second sway threshold value Tob to a value Tob2 that is greater than the initial setting value Tob0 and maintains it at that value.

[0108] In this example, the third threshold T3 corresponds to a traveling speed of 20 km / h. The determination value C3 is 0 when the rotation speed of the front wheel 11b is less than the third threshold T3, and is 1 when the rotation speed of the front wheel 11b is equal to or greater than the third threshold T3.

[0109] After the elapsed time t21, the rotation speed of the front wheel 11b drops below the third threshold T3, so the processing circuit 40 lowers the second oscillation threshold Tob to a value lower than the value Tob2. After the elapsed time t21, the absolute value of the oscillation amount of the oscillator 51 increases.

[0110] At elapsed time t22, the rear wheel 11a of the vehicle 1 begins to slip down, and from elapsed time t22 onwards, the absolute value of the amount of rocking of the rocking body 51 becomes equal to or greater than the first rocking threshold Toa. Furthermore, from elapsed time t22 onwards, the absolute value of the slip ratio increases rapidly, and the processing circuit 40 rapidly lowers the second rocking threshold Tob. From elapsed time t22 onwards until elapsed time t23, the second rocking threshold Tob is greater than the initial setting value Tob0. During the period in which the absolute value of the amount of rocking of the rocking body 51 is equal to or greater than the first rocking threshold Toa, it is less than the second rocking threshold Tob. Therefore, the processing circuit 40 determines that the vehicle 1 is not overturning.

[0111] The absolute value of the inertial force in the left-right direction increases rapidly just before elapsed time t23, and becomes equal to or greater than the first threshold value T1 at elapsed time t23. Therefore, the processing circuit 40 sets the second sway threshold value Tob to the initial setting value Tob0 at elapsed time t23. Because the second sway threshold value Tob is equal to or greater than the initial setting value Tob0 during the period from elapsed time t22 to elapsed time t23 (t23-t22), the processing circuit 40 determines that the vehicle 1 has overturned at elapsed time t23.

[0112] Therefore, in cases where the vehicle 1 rolls over at low speeds, the processing circuit 40 corrects the second sway threshold Tob so that it approaches the initial setting value Tob0 as the state of the vehicle 1 approaches rollover, and cancels the extension of the second sway threshold Tob from the initial setting value Tob0. This reduces the delay in the timing at which the processing circuit 40 determines that the vehicle 1 has rolled over relative to the timing at which the vehicle 1 actually enters a rollover state. Therefore, the correction of the second sway threshold Tob does not interfere with the determination that the vehicle 1 has actually rolled over.

[0113] 6 is a diagram showing an example of the process of correcting the second sway threshold Tob by the processing circuit 40 according to this embodiment when the vehicle 1 rolls over at a high speed. The high speed range is preferably a speed range of 80 km / h or higher, and more preferably a speed range of 100 km / h or higher. As shown in FIG. 6, the vehicle 1 experiences a state called a front-up, in which the front wheel 11b lifts off the road surface, at elapsed time t32, and then falls into a rollover state in which the body of the vehicle 1 touches the ground at elapsed time t33.

[0114] Up to elapsed time t31, which is before elapsed time t32, the absolute value of the lateral inertial force is equal to or less than the first threshold value T1, the rotational speed of the front wheel 11b is equal to or greater than the third threshold value T3, and the absolute value of the slip ratio is equal to or less than the second threshold value T2. Therefore, the processing circuit 40 sets the second sway threshold value Tob to a value Tob3 that is greater than the initial setting value Tob0 and maintains it at that value.

[0115] In this example, the third threshold T3 corresponds to a traveling speed of 30 km / h. The sixth threshold T6 corresponds to a traveling speed of 20 km / h. The judgment value C3 is 1 when the rotation speed of the front wheel 11b is equal to or greater than the third threshold T3, is 0 when the rotation speed of the front wheel 11b is equal to or less than the sixth threshold T6, and is a predetermined value greater than 0 and less than 1 when the rotation speed of the front wheel 11b is greater than the sixth threshold T6 and less than the third threshold T3. Therefore, the value Tob3 of the second sway threshold Tob can be greater than the value Tob2 in FIG. 5.

[0116] Between elapsed time t31 and elapsed time t32, the front wheel 11b of the vehicle 1 enters a slight front-up state at elapsed time t31, and then lands at elapsed time t3a. Furthermore, the front wheel 11b enters a front-up state again at elapsed time t3b, and then lands at elapsed time t3c. Furthermore, the front wheel 11b enters a slight front-up state again at elapsed time t3d, and then lands at elapsed time t3e. The front wheel 11b of the vehicle 1 enters a front-up state at elapsed time t32 and maintains the front-up state. Thereafter, at elapsed time t33, the vehicle 1 overturns, and the front wheel 11b touches the ground.

[0117] After elapsed time t32, the absolute value of the slip ratio increases rapidly and further increases beyond the second threshold value T2, so the processing circuit 40 rapidly reduces the second sway threshold value Tob and sets it to the initial setting value Tob0. Furthermore, since the period from elapsed time t32 to elapsed time t33 (t33-t32) is equal to or greater than the initial setting value Tob0, the processing circuit 40 determines that the vehicle 1 has overturned at elapsed time t33.

[0118] Therefore, in the case where the vehicle 1 rolls over at a high speed, when the vehicle 1 enters a state that may cause the vehicle 1 to roll over, such as a front-up state, the processing circuit 40 sets the second sway threshold Tob to the initial setting value Tob0 and cancels the extension of the second sway threshold Tob from the initial setting value Tob0. This reduces the delay in the timing at which the processing circuit 40 determines that the vehicle 1 has rolled over relative to the timing at which the vehicle 1 actually enters a rollover state. Therefore, the correction of the second sway threshold Tob does not interfere with the determination that the vehicle 1 has actually rolled over.

[0119] [Variation 1] A first modification of the embodiment will be described. The processing circuit according to this modification differs from the embodiment in that, in addition to the second sensor 60 of the embodiment, the detection results of another second sensor 60 are used to determine whether the vehicle 1 is not overturned. In the following, the differences between this modification and the embodiment will be described, and the description of the similarities between the embodiment and the modification will be omitted as appropriate.

[0120] 7 is a block diagram showing an example of the configuration of the control circuit 30 and the processing circuit 40 according to Modification 1. As shown in FIG. 7, the one or more second sensors 60 may include a front stroke sensor 63, a rear stroke sensor 64, or both. The one or more second sensors 60 may include a front air pressure sensor 65, a rear air pressure sensor 66, or both. In this modification, the one or more second sensors 60 include the front stroke sensor 63, the rear stroke sensor 64, the front air pressure sensor 65, and the rear air pressure sensor 66.

[0121] The front stroke sensor 63 detects the stroke amount due to the expansion and contraction of the front fork 104, which is the front suspension. The rear stroke sensor 64 detects the stroke amount due to the expansion and contraction of the rear suspension 106. The stroke sensors 63 and 64 output the detection results as estimated information to the processing circuit 40. The stroke sensors 63 and 64 are one of the sensors for driving control. Hereinafter, the "front fork 104" may be referred to as the "front suspension 104."

[0122] The front air pressure sensor 65 detects the air pressure of the tire of the front wheel 11b. The rear air pressure sensor 66 detects the air pressure of the tire of the rear wheel 11a. The air pressure sensors 65 and 66 output the detection results as estimated information to the processing circuit 40. The air pressure sensors 65 and 66 are one of the driving control sensors.

[0123] The processing circuit 40 estimates the likelihood that the vehicle 1 will not roll over based on the detection results of the front stroke sensor 63, the rear stroke sensor 64, or both.

[0124] The processing circuit 40 detects the extension / contraction cycle between the extension and contraction of the suspension 104 or 106 based on the detection results of the stroke sensor 63 or 64, and can estimate the likelihood that the vehicle 1 is not overturning based on the extension / contraction cycle. If the extension / contraction cycle is equal to or shorter than a predetermined cycle, it can be estimated that there is a high likelihood that the vehicle 1 is not overturning. The processing circuit 40 may estimate that there is a high likelihood that the vehicle 1 is not overturning when the extension / contraction cycle is equal to or shorter than a seventh threshold value T7. The processing circuit 40 may estimate that there is a high likelihood that the vehicle 1 is not overturning when the above-mentioned state continues for an estimation period ta. The above-mentioned case can occur when the vehicle 1 is traveling in a non-overturning state.

[0125] The processing circuit 40 may estimate the determination value C4 according to the extension / contraction cycle. The determination value C4 may represent the likelihood that the vehicle 1 is not overturned as a percentage or a ratio. In this modification, the determination value C4 takes a positive value indicating that the vehicle 1 is likely not overturned, but may also take a negative value indicating that the vehicle 1 is likely overturned.

[0126] The processing circuit 40 may set the judgment value C4 to a maximum value, such as 100%, when the extension / contraction cycle of the suspension 104 or 106 is equal to or less than a seventh threshold value T7. The processing circuit 40 may set the judgment value C4 to a maximum value when the above state continues over the estimation period ta. The processing circuit 40 may set the judgment value C4 to a smaller value as the extension / contraction cycle increases. The processing circuit 40 may correct the judgment value C4 according to the integral value of the extension / contraction cycle, past trends, changes over time, or a combination of two or more of these, or the like.

[0127] The processing circuit 40 detects the extension period during which one or both of the suspensions 104 and 106 maintain their maximum extension state based on the detection results of the stroke sensor 63 or 64, and can estimate the likelihood that the vehicle 1 is not overturning based on the extension period. If the extension period is equal to or shorter than a predetermined period, it can be estimated that there is a high likelihood that the vehicle 1 is not overturning. The processing circuit 40 may also estimate that there is a high likelihood that the vehicle 1 is not overturning if the extension period is equal to or shorter than an eighth threshold T8. In this modification, the processing circuit 40 makes the estimation based on the extension periods of both the suspensions 104 and 106. The above-described case can occur when the vehicle 1 in a non-overturning state jumps.

[0128] The processing circuit 40 may estimate the determination value C5 according to the extension / contraction cycle. The determination value C5 may represent the likelihood that the vehicle 1 is not overturned as a percentage or a ratio. In this modification, the determination value C5 takes a positive value indicating that the vehicle 1 is likely not overturned, but may also take a negative value indicating that the vehicle 1 is likely overturned.

[0129] The processing circuit 40 may set the judgment value C5 to a maximum value such as 100% when the extension period of the suspensions 104 and 106 is equal to or less than an eighth threshold T8. The processing circuit 40 may set the judgment value C5 to a smaller value as the extension period increases. The processing circuit 40 may correct the judgment value C5 in accordance with the integral of the extension period, past trends, changes over time, a combination of two or more of these, or the like.

[0130] The processing circuit 40 may estimate the likelihood that the vehicle 1 will not tip over based on the detection results of the air pressure sensors 65 and 66.

[0131] The processing circuit 40 detects the fluctuation period of the tire air pressure of one or both of the rear wheels 11a and the front wheels 11b based on the detection results of the air pressure sensors 65 and 66, and can estimate the likelihood that the vehicle 1 is not overturning based on the fluctuation period. If the fluctuation period is equal to or shorter than a predetermined period, it can be estimated that there is a high likelihood that the vehicle 1 is not overturning. The processing circuit 40 may also estimate that there is a high likelihood that the vehicle 1 is not overturning when the fluctuation period is equal to or shorter than a ninth threshold T9. The processing circuit 40 may also estimate that there is a high likelihood that the vehicle 1 is not overturning when the above-mentioned state continues for an estimation period ta. In this modification, the processing circuit 40 makes the estimation based on the tire air pressure of both the rear wheels 11a and the front wheels 11b. The above-mentioned case can occur when the vehicle 1 is traveling in a non-overturning state.

[0132] The processing circuit 40 may estimate the determination value C6 according to the fluctuation period. The determination value C6 may represent the likelihood that the vehicle 1 is not overturned as a percentage or a ratio. In this modification, the determination value C6 takes a positive value indicating that the vehicle 1 is likely not overturned, but may also take a negative value indicating that the vehicle 1 is likely overturned.

[0133] The processing circuit 40 may set the determination value C6 to a maximum value, such as 100%, when the fluctuation period of the tire air pressures of the rear wheels 11a and the front wheels 11b is equal to or less than the ninth threshold value T9. The processing circuit 40 may set the determination value C6 to a maximum value when the above state continues over the estimation period ta. The processing circuit 40 may set the determination value C6 to a smaller value as the fluctuation period increases. The processing circuit 40 may correct the determination value C6 in accordance with the integral value of the fluctuation period, past trends, changes over time, or a combination of two or more of these, or the like.

[0134] Based on the detection results of the air pressure sensors 65 and 66, the processing circuit 40 detects the decompression period from when the air pressure in both the rear wheel 11a and the front wheel 11b tires drops until the air pressure in both the rear wheel 11a and the front wheel 11b tires starts to increase, and can estimate the likelihood that the vehicle 1 is not tipping over based on the decompression period. If the decompression period is equal to or shorter than a predetermined period, it can be estimated that there is a high likelihood that the vehicle 1 is not tipping over. The processing circuit 40 may estimate that there is a high likelihood that the vehicle 1 is not tipping over when the decompression period is equal to or shorter than a tenth threshold T10. The above-mentioned case can occur when the vehicle 1 in a non-tipping state jumps.

[0135] The processing circuit 40 may estimate the determination value C7 depending on the decompression period. The determination value C7 may represent the likelihood that the vehicle 1 is not overturned as a percentage or a ratio. In this modification, the determination value C7 takes a positive value indicating that the vehicle 1 is likely not overturned, but may also take a negative value indicating that the vehicle 1 is likely overturned.

[0136] The processing circuit 40 may set the determination value C7 to a maximum value such as 100% when the depressurization period of the rear wheel 11a and the front wheel 11b is equal to or shorter than the tenth threshold T10. The processing circuit 40 may set the determination value C7 so that it decreases as the depressurization period increases. The processing circuit 40 may correct the determination value C7 in accordance with the integrated value of the depressurization period, past trends, changes over time, or a combination of two or more of these, etc.

[0137] The processing circuit 40 corrects the overturn condition based on one or more estimated factors related to the horizontal force acting on the vehicle 1, the traveling speed of the vehicle 1, and the slip ratio of the vehicle 1, as well as the expansion / contraction state of the suspension of the vehicle 1 and the air pressure of the tires of the vehicle 1. In this modification, the determination value Ck of the second sway threshold Tob includes determination values ​​C1 to C7.

[0138] Although not limited thereto, in this modification, the judgment values ​​C4 to C7 may be used as additive elements in the relational expression for the second fluctuation threshold Tob, "Tob=Tob0×(1+f(Ck))." The judgment values ​​C4 to C7 may also be used as other calculation elements, or may be combined with other judgment values ​​through calculation.

[0139] The determination value C4 may be set to a predetermined value greater than 0, such as "1," when the extension / contraction period is equal to or less than the seventh threshold value T7, and may be set to "0" when the extension / contraction period is greater than the seventh threshold value T7. The determination value C4 may be set to decrease in stages as the extension / contraction period increases.

[0140] For example, one or more judgment values ​​C4 may be set in the range above the seventh threshold T7. The judgment value C4 may be set to "1" for a range of 0 or more and the seventh threshold T7 or less, set to "0" for a range of 0 or more and the eleventh threshold T11 or more, and set to a predetermined value above 0 and less than 1 for a range of above the seventh threshold T7 and the eleventh threshold T11 or less. The eleventh threshold T11 is greater than the seventh threshold T7. Alternatively or in addition to the above, one or more judgment values ​​C4 may be set in the range of 0 or more and the seventh threshold T7 or less. The processing circuit 40 may determine a judgment value corresponding to the extension / contraction cycle from among a plurality of judgment values ​​C4 corresponding to each of a plurality of ranges.

[0141] The judgment value C5 may be set to a predetermined value greater than 0, such as "1," when the extension period is equal to or less than the eighth threshold T8, and may be set to "0" when the extension period is greater than the eighth threshold T8. The judgment value C5 may be set to gradually decrease as the extension period becomes longer.

[0142] For example, one or more judgment values ​​C5 may be set in the range above the eighth threshold T8. The judgment value C5 may be set to "1" for a range greater than or equal to 0 and less than or equal to the eighth threshold T8, set to "0" for a range greater than the twelfth threshold T12, and set to a predetermined value greater than 0 and less than 1 for a range greater than the eighth threshold T8 and less than or equal to the twelfth threshold T12. The twelfth threshold T12 is greater than the eighth threshold T8. Alternatively or in addition to the above, one or more judgment values ​​C5 may be set in the range greater than or equal to 0 and less than or equal to the eighth threshold T8. The processing circuit 40 may determine a judgment value corresponding to the extension period from among a plurality of judgment values ​​C5 corresponding to each of a plurality of ranges.

[0143] The judgment value C6 may be set to a predetermined value greater than 0, such as "1," when the fluctuation period is equal to or less than the ninth threshold T9, and may be set to "0" when the fluctuation period is greater than the ninth threshold T9. The judgment value C6 may be set to decrease in stages as the fluctuation period increases.

[0144] For example, one or more judgment values ​​C6 may be set in a range exceeding the ninth threshold T9. The judgment value C6 may be set to "1" for a range of 0 or more and equal to or less than the ninth threshold T9, set to "0" for a range of 0 or more and equal to or greater than the thirteenth threshold T13, and set to a predetermined value greater than 0 and less than 1 for a range of 0 or more and equal to or less than the thirteenth threshold T13. The thirteenth threshold T13 is greater than the ninth threshold T9. Alternatively or in addition to the above, one or more judgment values ​​C6 may be set in a range of 0 or more and equal to or less than the ninth threshold T9. The processing circuit 40 may determine a judgment value corresponding to the fluctuation period from among a plurality of judgment values ​​C6 corresponding to each of a plurality of ranges.

[0145] The determination value C7 may be set to a predetermined value greater than 0, such as "1," when the decompression period is equal to or less than the tenth threshold T10, and may be set to "0" when the decompression period exceeds the tenth threshold T10. The determination value C7 may be set to gradually decrease as the decompression period becomes longer.

[0146] For example, one or more judgment values ​​C7 may be set in a range above the tenth threshold T10. The judgment value C7 may be set to "1" for a range of 0 or more and equal to or less than the tenth threshold T10, set to "0" for a range of 0 or more and equal to or greater than the fourteenth threshold T14, and set to a predetermined value above 0 and less than 1 for a range above the tenth threshold T10 and equal to or less than the fourteenth threshold T14. The fourteenth threshold T14 is greater than the tenth threshold T10. Alternatively or in addition to the above, one or more judgment values ​​C7 may be set in a range of 0 or more and equal to or less than the tenth threshold T10. The processing circuit 40 may determine a judgment value corresponding to the decompression period from among a plurality of judgment values ​​C7 corresponding to each of a plurality of ranges.

[0147] In this modification, f(Ck) is defined as f(Ck)=C1+C2×C3+C4+C5+C6+C7, and the second sway threshold Tob can be defined as Tob=Tob0×(1+C1+C2×C3+C4+C5+C6+C7). The processing circuit 40 uses this second sway threshold Tob to determine whether the vehicle 1 has not rolled over, as in the embodiment. The second sway threshold Tob in this modification is corrected using the determination values ​​of more estimation elements than in the embodiment, thereby improving the accuracy of determining whether the vehicle 1 has not rolled over.

[0148] [Variation 2] A second modification of the embodiment will now be described. The processing circuit of this modification differs from the embodiment in that it corrects the degree of likelihood that the vehicle 1 will not roll over, which is estimated with respect to the estimation elements. Below, the differences between this modification and the embodiment and the first modification will be described, and descriptions of the same points as the embodiment or the first modification will be omitted as appropriate.

[0149] In this modification, the processing circuit 40 corrects the estimated likelihood that the vehicle 1 will not tip over, based on the force acting in the left-right direction on the vehicle 1. For the correction, the processing circuit 40 uses one or both of the inertial force in the up-down direction and the inertial force in the front-to-rear direction acting on the vehicle 1. In this modification, both are used.

[0150] Processing circuit 40 estimates the attitude of vehicle 1 based on the detection results of inertial force sensor 61. Processing circuit 40 detects the inertial forces acting in the up-down direction and the fore-and-aft direction on vehicle 1 based on the attitude of vehicle 1 and the detection results of acceleration in each detection axis direction of inertial force sensor 61. The inertial forces acting in the up-down direction on vehicle 1 are inertial forces acting in the vertical direction and in the up-and-down direction of vehicle 1. The inertial forces acting in the fore-and-aft direction on vehicle 1 are inertial forces acting in the horizontal direction and in the fore-and-aft direction of vehicle 1.

[0151] The vehicle 1 travels while receiving a reaction force from the road surface. Therefore, when the vehicle 1 is traveling, the inertial force acting on the vehicle 1 in the vertically upward direction is not balanced with the inertial force acting on the vehicle 1 in the vertically downward direction. Therefore, if the inertial force acting on the vehicle 1 in the vertical direction is not zero, it can be estimated that there is a high possibility that the vehicle 1 is traveling in a non-overturned state. The processing circuit 40 may estimate that there is a high possibility that the vehicle 1 is not overturned when the absolute value of the vertical inertial force, which is the inertial force acting on the vehicle 1 in the vertical direction, is equal to or greater than the vertical threshold value Tud. The processing circuit 40 may estimate that there is a high possibility that the vehicle 1 is not overturned when the above state continues for the estimation period ta.

[0152] The processing circuit 40 may estimate the determination value C8 according to the vertical inertial force. The determination value C8 may represent the likelihood that the vehicle 1 is not overturning as a percentage or a ratio. In this modification, the determination value C8 takes a positive value indicating that the vehicle 1 is likely not overturning, but may also take a negative value indicating that the vehicle 1 is likely overturning.

[0153] The processing circuit 40 may determine the judgment value C8 to be a maximum value, such as 100%, when the absolute value of the vertical inertia force is equal to or greater than the vertical threshold value Tud. The processing circuit 40 may determine the judgment value C8 to be a maximum value when the above state continues over the estimation period ta. The processing circuit 40 may determine the judgment value C8 so that it increases as the absolute value of the vertical inertia force increases. The processing circuit 40 may correct the judgment value C8 in accordance with the integrated value of the vertical inertia force, past trends, changes over time, or a combination of two or more of these, or the like.

[0154] When the vehicle 1 is in the process of tipping over or is already tipping over, it cannot move forward using the driving force of the rear wheel 11a, and sufficient braking is not applied to the front wheel 11b and rear wheel 11a. In such a state, the inertial force in the fore-and-aft direction acting on the vehicle 1 may become zero. On the other hand, while the vehicle 1 is moving forward using the driving force of the rear wheel 11a, it may be subjected to an inertial force in the fore-and-aft direction. Therefore, if the inertial force acting on the vehicle 1 in the fore-and-aft direction is not zero, it can be estimated that there is a high possibility that the vehicle 1 is moving in a non-tipping state.

[0155] The processing circuit 40 may estimate that there is a high possibility that the vehicle 1 is not overturning when the absolute value of the longitudinal inertial force, which is the inertial force acting on the vehicle 1 in the longitudinal direction, is equal to or greater than the longitudinal threshold value Tfb. The processing circuit 40 may estimate that there is a high possibility that the vehicle 1 is not overturning when the above state continues for the estimation period ta.

[0156] The processing circuit 40 may estimate the determination value C9 according to the longitudinal inertial force. The determination value C9 may represent the likelihood that the vehicle 1 is not overturning as a percentage or a ratio. In this modification, the determination value C9 takes a positive value indicating that the vehicle 1 is likely not overturning, but may also take a negative value indicating that the vehicle 1 is likely overturning.

[0157] The processing circuit 40 may set the judgment value C9 to a maximum value, such as 100%, when the absolute value of the longitudinal inertial force is equal to or greater than the longitudinal threshold value Tfb. The processing circuit 40 may set the judgment value C9 to a maximum value when the above state continues over the estimation period ta. The processing circuit 40 may set the judgment value C9 to a smaller value as the absolute value of the longitudinal inertial force decreases. The processing circuit 40 may correct the judgment value C9 in accordance with the integrated value of the longitudinal inertial force, past trends, changes over time, or a combination of two or more of these, or the like.

[0158] The processing circuit 40 applies one or both of the determination value C8 related to the vertical inertial force and the determination value C9 related to the longitudinal inertial force to the relational expression "Tob=Tob0×(1+f(Ck))" for the second fluctuation threshold Tob. In this modification, the processing circuit 40 applies the determination values ​​C8 and C9 to the determination value C1.

[0159] The judgment value C8 is combined with the judgment value C1 as a multiplication factor. Therefore, the judgment value C1 is corrected to increase or decrease depending on the degree of possibility that the vehicle 1 will not overturn, as indicated by the judgment value C8. The judgment value C8 may be set to a predetermined value greater than 0, such as "1," when the absolute value of the vertical inertia force is equal to or greater than the upper and lower thresholds Tud, and may be set to "0" when the absolute value of the vertical inertia force is less than the upper and lower thresholds Tud. The judgment value C8 may be set to increase in stages as the absolute value of the vertical inertia force increases.

[0160] For example, one or more judgment values ​​C8 may be set in the range below the upper and lower thresholds Tud. The judgment value C8 may be set to "0" for a range greater than or equal to 0 and less than the second upper and lower thresholds Tud, set to "1" for a range greater than the first upper and lower thresholds Tud, and set to a predetermined value greater than 0 and less than 1 for a range greater than the second upper and lower thresholds Tud and less than or equal to the first upper and lower thresholds Tud. The second upper and lower thresholds Tud are smaller than the first upper and lower thresholds Tud. Alternatively or in addition to the above, one or more judgment values ​​C8 may be set in the range greater than the first upper and lower thresholds Tud. The processing circuit 40 may determine a judgment value corresponding to the upper and lower inertial force from among a plurality of judgment values ​​C9 corresponding to each of a plurality of ranges.

[0161] The judgment value C9 is combined with the judgment value C1 as a multiplication factor. Therefore, the judgment value C1 is corrected to increase or decrease depending on the degree of possibility that the vehicle 1 will not roll over, which is indicated by the judgment value C8. The judgment value C9 may be set to a predetermined value greater than 0, such as "1," when the absolute value of the longitudinal inertial force is equal to or greater than the longitudinal threshold value Tfb, and may be set to "0" when the absolute value of the longitudinal inertial force is less than the longitudinal threshold value Tfb. The judgment value C9 may be set to increase in stages as the absolute value of the longitudinal inertial force increases.

[0162] For example, one or more judgment values ​​C9 may be set in a range below the longitudinal threshold Tfb. The judgment value C9 may be set to "0" for a range greater than or equal to 0 and less than the second longitudinal threshold Tfba, set to "1" for a range greater than the first longitudinal threshold Tfb, and set to a predetermined value greater than 0 and less than 1 for a range greater than the second longitudinal threshold Tfba and less than or equal to the first longitudinal threshold Tfb. The second longitudinal threshold Tfba is smaller than the first longitudinal threshold Tfb. Alternatively or in addition to the above, one or more judgment values ​​C9 may be set in a range greater than the first longitudinal threshold Tfb. The processing circuit 40 may determine a judgment value corresponding to the longitudinal inertial force from among a plurality of judgment values ​​C9 corresponding to each of a plurality of ranges.

[0163] When the embodiment is used as a base, f(Ck) according to this modification can be defined as f(Ck) = C1 × C8 × C9 + C2 × C3, while f(Ck) based on Modification 1 can be defined as f(Ck) = C1 × C8 × C9 + C2 × C3 + C4 + C5 + C6 + C7. The second sway threshold Tob based on the embodiment can be defined as Tob = Tob0 × (1 + C1 × C8 × C9 + C2 × C3), while the second sway threshold Tob based on Modification 1 can be defined as Tob = Tob0 × (1 + C1 × C8 × C9 + C2 × C3 + C4 + C5 + C6 + C7). The processing circuit 40 uses such second sway threshold Tob to determine whether the vehicle 1 is not overturning, similarly to the embodiment or Modification 1. The second sway threshold value Tob according to this modification is corrected using the judgment values ​​of more estimation elements than in the embodiment and modification 1, and therefore the accuracy of judging whether the vehicle 1 has not rolled over can be improved.

[0164] [others] Although exemplary embodiments and modifications of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and modifications. In other words, various modifications and improvements are possible within the scope of the present disclosure. For example, various modifications made to the embodiments or modifications, and forms constructed by combining components of different embodiments and modifications, are also included within the scope of the present disclosure.

[0165] For example, in the embodiment and modified example, the processing circuit 40 corrects the fall condition by correcting the second fluctuation threshold Tob related to the fluctuation period of the oscillating body 51 of the fall sensor 50, but this is not limited to this. The processing circuit 40 may also correct the fall condition by correcting the first fluctuation threshold Toa related to the amount of oscillation of the oscillating body 51 of the fall sensor 50. In this case, the first fluctuation threshold Toa may be defined by the same relational expression as the second fluctuation threshold Tob. For example, the first fluctuation threshold Toa may be defined by the relational expression Toa = Toa0 × (1 + g(Ck)) using the initial setting value Toa0 of the first fluctuation threshold and the judgment value Ck of the estimation element. g(Ck) is a function with the judgment values ​​C1 to Cn as elements. The function g(Ck) and the judgment value Ck may be defined in the same way as the function f(Ck) and the judgment value Ck of the second fluctuation threshold Tob.

[0166] When the determination value Ck is greater than 0, the first sway threshold Toa can be corrected by the determination value Ck so as to be greater than the initial setting value Toa0. Therefore, when there is a possibility that the vehicle 1 will not roll over, the first sway threshold Toa can be corrected so as to be greater than the initial setting value Toa0, making it difficult for the rollover condition to be satisfied.

[0167] FIG. 8 is a diagram similar to FIG. 4 illustrating an example of the correction process for the first sway threshold Toa performed by the processing circuit 40. As shown in FIG. 8, the first sway threshold Toa is plotted as a graph of the sway amount. The behavior of the sway amount, lateral inertial force, rotational speed, and slip ratio in FIG. 8 is the same as that in FIG. 4. Therefore, the processing circuit 40 corrects the first sway threshold Toa to a value Toa1 greater than the initial setting value Toa0 before elapsed time t11, and maintains the value at that value. During the period (t12-t11), the rocking body 51 maintains a sway amount equal to or greater than the initial setting value Toa0 and less than the corrected first sway threshold Toa1 for a period equal to or greater than the second sway threshold Tob. Therefore, the processing circuit 40 determines that the vehicle 1 is not overturning.

[0168] In the embodiment and the modified example, the processing circuit 40 corrects the second sway threshold Tob so as to increase it from the initial setting value Tob0 based on the detection result of the second sensor 60, but this is not limited to this. For example, when the processing circuit 40 can estimate that there is a high possibility that the vehicle 1 has overturned based on the detection result of the second sensor 60, the processing circuit 40 may correct the second sway threshold Tob so as to decrease it from the initial setting value Tob0. Alternatively, the processing circuit 40 may correct the first sway threshold Toa so as to decrease it from the initial setting value. In this case, the judgment value Ck may be a negative value. The judgment value Ck may be a subtraction element, a multiplication element, or a division element of the initial setting value of the sway threshold.

[0169] In the embodiment and the modified example, the processing circuit 40 uses various thresholds to determine the judgment value Ck for correcting the sway threshold, but the thresholds may be fixed or variable. For example, if the amount of change per time of the estimation element or the amount of change per time in the behavior of the vehicle 1 is a large amount that exceeds a predetermined amount, it can be estimated that there is a high possibility that the vehicle 1 has rolled over. If the amount of change exceeds the predetermined amount, the processing circuit 40 may vary the threshold so that it is estimated that there is a low possibility that the vehicle 1 has not rolled over, that is, it becomes difficult to determine that the vehicle 1 has not rolled over. The processing circuit 40 may detect the behavior of the vehicle 1 based on the detection result of the inertial force sensor 61.

[0170] In the embodiment and the modified example, processing circuitry 40 applies the determination value to the initial setting value so as to increase the initial setting value of the sway threshold in correcting the sway threshold, but is not limited to this. For example, processing circuitry 40 may apply the determination value to the initial setting value so as to subtract, add, or subtract from the initial setting value. The method of applying the determination value to the initial setting value may be determined depending on the characteristics of the estimation element of the determination value.

[0171] In the embodiment and the modified example, the processing circuit 40 corrects the tipping condition by correcting a sway threshold, such as the second sway threshold Tob, based on the slip ratio, but this is not limiting. For example, the processing circuit 40 may use the wheel speed difference instead of or in addition to the slip ratio to correct the sway threshold. The processing circuit 40 may estimate that the smaller the wheel speed difference, the more likely the vehicle 1 will not tip over. The processing circuit 40 may determine and use a judgment value for the wheel speed difference when correcting the sway threshold. The processing circuit 40 may determine the judgment value to be a predetermined value greater than 0, such as "1," when the wheel speed difference is equal to or less than a threshold value close to 0, and may determine the judgment value to be "0" when the absolute value of the wheel speed difference is greater than 0 or exceeds the threshold. The processing circuit 40 may determine the judgment value so that it gradually decreases as the absolute value of the wheel speed difference increases from 0.

[0172] In the embodiment and modified example, the processing circuit 40 corrects the tipping condition by correcting a sway threshold, such as the second sway threshold Tob, based on the inertial force acting in the left-right direction on the vehicle 1, but is not limited to this. For example, the processing circuit 40 may use one or more of the attitude, acceleration, and angular velocity of the vehicle 1 instead of or in addition to the inertial force to correct the sway threshold. The processing circuit 40 may detect the attitude, acceleration, and angular velocity of the vehicle 1 based on the detection results of the inertial force sensor 61. The processing circuit 40 may determine and use one or more determination values ​​of the attitude, acceleration, and angular velocity of the vehicle 1 when correcting the sway threshold.

[0173] For example, the deviation of the posture of the vehicle 1 from an upright posture or the posture state of the vehicle 1 may be detected. Examples of the posture state of the vehicle 1 may include a jackknife state in which only the front wheel 11b touches the ground, a wheelie state in which only the rear wheel 11a touches the ground, and a normal state in which both the front wheel 11b and the rear wheel 11a touch the ground. The deviation correlates with whether the vehicle 1 is tipping over or not. In a jackknife state or a wheelie state, the vehicle 1 does not tip over even if the amount of lean of the body of the vehicle 1 is large. Therefore, the judgment value can be set in association with the deviation and can be set in association with the posture state. The acceleration of the vehicle 1 may be detected as the acceleration of the vehicle 1 in the lateral and horizontal directions. Such acceleration correlates with the inertial force acting on the vehicle 1 in the lateral directions. Therefore, the judgment value can be set in association with the acceleration. The angular velocity of the vehicle 1 may be detected as the angular velocity of the vehicle 1 around an axis in the longitudinal and horizontal directions. Such an angular velocity correlates with the rotational velocity in the rolling direction, which is the direction in which the body of the vehicle 1 overturns. Therefore, the determination value can be set in association with the angular velocity.

[0174] The processing circuit 40 according to the embodiment and the modified example may detect the specific running state of the vehicle 1 based on the detection result of the second sensor 60. The processing circuit 40 may use a judgment value of the specific running state of the vehicle 1 when correcting the sway threshold. The processing circuit 40 may determine the judgment value based on whether the running state of the vehicle 1 is the specific running state. When the running state of the vehicle 1 is the specific running state, the processing circuit 40 may increase the sway threshold to make it less likely that the vehicle 1 has turned over.

[0175] Examples of specific driving states of the vehicle 1 include a steady circle driving state and a U-turn driving state. The processing circuit 40 can determine that the vehicle 1 is in a steady circle driving state or a U-turn driving state when it determines that the direction of the resultant force of the inertial force acting in the left-right direction on the vehicle 1 and the inertial force acting in the up-down direction on the vehicle 1 is along the center line of the vehicle 1. The center line is based on the vehicle 1 and extends vertically when the vehicle 1 is in an upright position. U-turn driving can include steady circle driving as a part of the driving state. In steady circle driving and U-turn driving, the inertial force acting in the left-right direction on the vehicle 1 may exceed the first threshold T1, the slip ratio may exceed the second threshold T2, and the driving speed may be less than the third threshold T3, but this can make it less likely that the vehicle 1 is determined to be overturned.

[0176] In the embodiment and the modified example, the processing circuit 40 corrects the sway threshold for the overturn condition using the detection results of the multiple second sensors 60, but this is not limiting. The processing circuit 40 may correct the sway threshold using the detection result of one second sensor 60. For example, the processing circuit 40 may correct the sway threshold using only the detection result of the inertial force sensor 61. In this case, the sway threshold may be corrected based on the determination value C1 of the force acting in the left-right direction on the vehicle 1. For example, the processing circuit 40 may correct the sway threshold using only the detection result of the wheel speed sensor 62. In this case, the sway threshold may be corrected based on the slip ratio determination value C2, or based on the slip ratio determination value C2 and the traveling speed determination value C3.

[0177] In either case, the processing circuit 40 can correct the rollover condition so that it is less likely that the vehicle 1 is determined to be rolling over when there is a high probability that the vehicle 1 is not rolling over. The processing circuit 40 may correct the sway threshold using only the detection results of the stroke sensors 63 and 64 or only the detection results of the air pressure sensors 65 and 66. The processing circuit 40 may correct the sway threshold using one or more of the determination values ​​C1 to C9.

[0178] In the embodiment and the modified example, the processing circuit 40 is configured to, at the timing when the determination period tb has elapsed, determine whether the second fluctuation threshold Tob of the overturn condition should be corrected, correct the second fluctuation threshold Tob, and determine whether the vehicle 1 has overturned based on a comparison between the second fluctuation threshold Tob and the elapsed time, but is not limited to this. The timing of determining whether the second fluctuation threshold Tob should be corrected and the timing of correcting the second fluctuation threshold Tob may be different from the timing of determining whether the vehicle 1 has overturned.

[0179] In the embodiment and the modified example, the processing circuit 40 determines whether or not to correct the second fluctuation threshold Tob and performs the correction for each correction period tc, regardless of whether the amount of fluctuation detected by the fall sensor 50 is equal to or greater than the first fluctuation threshold Toa. However, this is not limited to this. For example, the processing circuit 40 may start measuring the correction period tc in relation to the amount of fluctuation detected by the fall sensor 50, and determine whether or not to correct the second fluctuation threshold Tob and perform the correction each time the correction period tc elapses. For example, the timing to start measuring the correction period tc may be the timing when the amount of fluctuation reaches a predetermined ratio of the first fluctuation threshold Toa. The predetermined ratio may be selected from a range greater than 0% and less than or equal to 100%.

[0180] In the embodiment and the modified example, when a correction period tc has elapsed, the processing circuit 40 determines whether or not the second fluctuation threshold Tob should be corrected and performs the correction process using the detection results of the second sensor 60 acquired during the most recent correction period tc. However, this is not limited to this. The processing circuit 40 may use the detection results of the second sensor 60 acquired during any period for the above process. For example, the processing circuit 40 may use the detection results of the second sensor 60 acquired during the most recent correction period tc and one or more correction periods tc prior to the correction period tc, or may use the detection results of the second sensor 60 acquired during one or more correction periods tc prior to the most recent correction period tc. The processing circuit 40 may vary the period for acquiring the detection results of the second sensor 60 depending on the estimation factor.

[0181] In the embodiment and the modified example, the control circuit 30 controls the output of the prime mover 20 so as to output an appropriate driving force in accordance with the traveling speed of the vehicle 1 based on the detection results of the driven wheel speed sensor 621. The function of the control circuit 30 is not limited to the above. For example, the control circuit 30 may control the behavior of the vehicle 1 by controlling the output of the prime mover 20 based on the detection results of the inertial force sensor 61. The control circuit 30 may also control the behavior of the vehicle 1 by controlling an actuator other than the prime mover 20. For example, either or both of the front suspension 104 and the rear suspension 106 may be controlled by an actuator to control the damping force and stroke amount of the extension and compression motions. The control circuit 30 may control the behavior of the vehicle 1 by controlling the operation of the actuators of the suspensions 104 and 106 based on the detection results of the stroke sensors 63 and 64.

[0182] Control circuit 30 may control the output of prime mover 20 and a brake actuator that activates the brakes of vehicle 1 based on the detection results of inertial force sensor 61 and wheel speed sensor 62. Control circuit 30 may control the output of prime mover 20 and the amount of brake operation in conjunction with each other. For example, when vehicle 1 is turning or performing a wheelie, control circuit 30 may assist the driver in operating the accelerator and brakes of prime mover 20 based on the detection results of inertial force sensor 61 and wheel speed sensor 62.

[0183] In the embodiment and the modified example, the vehicle 1 is provided with a drive wheel speed sensor 622 that detects the rotational speed of the rear wheels 11 a of the vehicle 1, but the drive wheel speed sensor 622 may be configured to detect the rotational speed of the prime mover 20 that drives the rear wheels 11 a. In this case, the drive wheel speed sensor 622 may be a sensor similar to the sensor exemplified as the wheel speed sensor 62. The function of the drive wheel speed sensor 622 may be realized by the control circuit 30. The control circuit 30 may estimate the rotational speed of the prime mover 20 based on a command value that controls the prime mover 20.

[0184] In the embodiment and modified examples, a motorcycle is exemplified as the vehicle 1, but the vehicle 1 is not limited thereto. The processing circuit 40, its functions, and the forwarding determination method according to the present disclosure can be applied to various vehicles 1 other than motorcycles. The vehicle 1 may be any vehicle that can carry one or more people and has a structure that can tip over. Examples of the vehicle 1 may include a car, a vessel, and various other forms of mobility. Examples of vehicles may include a motorcycle, a moped, an electrically assisted bicycle, and an automobile. A vehicle may include two or more wheels. Examples of automobiles may include a passenger car, a freight vehicle, a passenger bus, a public transport vehicle, an all-terrain vehicle, and a utility vehicle. An all-terrain vehicle may be a vehicle capable of off-road driving. Examples of vessels may include a cargo ship, a passenger ship, a work boat, a fishing boat, a pleasure boat, and a personal watercraft. A vessel may include one or more propulsion bodies.

[0185] The vehicle 1 may be a lean vehicle that leans when turning, or a vehicle that does not lean when turning. Lean vehicles include saddle-ride vehicles. Examples of saddle-ride vehicles include motorcycles, mopeds, electrically assisted bicycles, and personal watercraft. An overturned state of the vehicle 1 as a lean vehicle may be a state in which the side of the vehicle 1 comes into contact with the ground or water surface, making it unable to run or navigate. An overturned state of the vehicle 1 that is not a lean vehicle may be a state in which the top, front, or rear of the vehicle 1 comes into contact with the ground or water surface in addition to the side of the vehicle 1. Examples of overturned states of the vehicle 1 that is not a lean vehicle may include a rollover state and a capsized state. Examples of overturned states of the vehicle 1 may include a state in which the drive wheels come off the ground due to a change in the attitude of the vehicle 1 as a car, and a state in which a propulsion body such as a propeller or impeller is exposed above the water surface due to a change in the attitude of the vehicle 1 as a watercraft such as a personal watercraft.

[0186] In the embodiment and modified examples, the vehicle 1 includes an internal combustion engine as the prime mover 20, but is not limited to this. Examples of the prime mover 20 may include a fluid machine that converts fluid energy into mechanical energy, a heat engine that converts thermal energy into mechanical energy, and an electric motor that converts electrical energy into mechanical energy. The vehicle 1 may include one or more prime movers 20. For example, the multiple prime movers 20 may operate the same part of the vehicle 1, or may operate two or more different parts of the vehicle 1. For example, the multiple prime movers 20 may individually drive multiple wheels 11 included in the drive structure 10. One prime mover 20 of the two or more prime movers 20 may drive another prime mover 20. For example, the prime mover 20 as an internal combustion engine may transmit rotational power to the drive structure 10, the prime mover 20 as a rotating electric machine, or both. The internal combustion engine may drive a rotating electric machine and cause the rotating electric machine to generate electrical energy.

[0187] The internal combustion engine serving as prime mover 20 may have any known structure. The internal combustion engine operates by receiving a supply of fuel. The fuel used by the internal combustion engine may be any fuel, such as fuels containing hydrocarbon compounds such as gasoline, ethanol, propane gas, and methane, fuels derived from animals and plants such as biofuels, or non-carbon fuels such as hydrogen.

[0188] For example, the cylinder structure of the internal combustion engine may be either a single-cylinder or a multi-cylinder structure, and the internal combustion engine may be either a four-stroke engine or a two-stroke engine.

[0189] The structure of the rotating electric machine serving as prime mover 20 may be any existing structure. For example, the rotating electric machine may have an inner rotor structure in which the rotor is located inside the stator and includes a rotor that rotates integrally with the drive shaft, or an outer rotor structure in which the rotor is located outside the stator. The rotating electric machine may generate electric power by rotating the rotor when supplied with electric power, and forcibly rotating the rotor via the drive shaft. The rotating electric machine may transmit the rotational power of the drive shaft to the drive wheels of drive structure 10. The rotating electric machine may generate electric power by rotating the drive shaft by drive structure 10, an internal combustion engine, or both that operate while vehicle 1 is moving, and supply the electric power to a battery provided in vehicle 1.

[0190] The vehicle 1 may be a vehicle equipped with only an internal combustion engine as the prime mover 20, an EV vehicle equipped with only a rotating electric machine as the prime mover 20, or a hybrid vehicle equipped with an internal combustion engine and a rotating electric machine as the prime mover 20.

[0191] Examples of various aspects of the technology of the present disclosure are listed below. In this specification and claims, the expressions "in the case of A" and "when A" include the meaning "in response to A being the case" and can be replaced with the expression "in response to A being the case."

[0192] A rollover determination method according to a first aspect of the present disclosure includes obtaining a detection result from a first sensor that detects the amount of swing of a rocking body that rocks in response to a change in the posture of the vehicle; obtaining a detection result from one or more second sensors that are separate from the first sensor and that detect estimated information for estimating the state of the vehicle; determining that the vehicle has rolled over if the amount of swing of the rocking body satisfies a predetermined rollover condition based on the detection result of the first sensor; and correcting the rollover condition based on the detection result of the second sensor.

[0193] According to the first aspect, the overturn condition is corrected according to the estimated state of the vehicle. By correcting the condition for determining whether or not the vehicle has overturned according to the state of the vehicle in this way, it is possible to more appropriately determine whether or not the vehicle has overturned in a situation where an error in determining whether or not the vehicle has overturned may occur, thereby improving the accuracy of determining whether or not the vehicle has overturned. A part or all of the overturn determination method of the present disclosure may be realized by, for example, a CPU, a circuit such as an LSI, an IC card, or a standalone module. The multiple elements included in the overturn determination method of the present disclosure may be realized by a single device, or may be shared and realized by two or more devices.

[0194] In the first aspect above, in the fall determination method according to the second aspect of the present disclosure, the one or more second sensors may include a sensor used to control the behavior of the vehicle while it is moving.

[0195] According to the second aspect described above, by using the detection results of a sensor for controlling the behavior of the vehicle while it is moving to determine whether the vehicle has rolled over, the cost required for determining whether the vehicle has rolled over can be reduced compared to when a dedicated sensor is used to increase the accuracy of determining whether the vehicle has rolled over.

[0196] In the first or second aspect described above, in a fall determination method according to a third aspect of the present disclosure, the one or more second sensors may include a sensor that estimates an upright state of the vehicle while it is moving.

[0197] According to the third aspect, by determining that the moving vehicle is in an upright state, it is possible to more easily prevent erroneous detection of tipping by the first sensor. For example, when it is determined that the moving vehicle is in an upright state, it may be more difficult to determine that the vehicle has tipped over than when it is determined that the vehicle is not in an upright state.

[0198] In any of the above first to third aspects, the fall determination method according to a fourth aspect of the present disclosure further includes estimating, based on the detection results of the one or more second sensors, whether or not the movement of the vehicle is continuing due to the rotation of drive wheels that rotate due to the transmitted driving force to move the vehicle, and by correcting the fall condition, if it is estimated that the movement of the vehicle is continuing due to the rotation of the drive wheels, the fall condition may be corrected so that it becomes more difficult to determine that the vehicle has fallen compared to a state in which the movement of the vehicle is not continuing due to the rotation of the drive wheels.

[0199] According to the fourth aspect, it is possible to make it difficult to determine that the vehicle is in an overturned state based on the detection result by the first sensor while the vehicle is continuing to move, thereby preventing an erroneous determination that the vehicle is in an overturned state while the vehicle is continuing to move.

[0200] In any of the first to fourth aspects described above, in a fall determination method according to a fifth aspect of the present disclosure, the vehicle is a lean vehicle that tilts when turning, and the one or more second sensors include an inertial force sensor that detects a force applied to the vehicle or an attitude of the vehicle, and the fall determination method may include correcting the fall condition based on a detection result of the inertial force sensor.

[0201] According to the fifth aspect, by detecting the force applied to the vehicle or the attitude of the vehicle, it is possible to estimate whether the vehicle is continuing to move, and the overturning condition is corrected according to the estimation result. This makes it possible to estimate whether the vehicle is continuing to move, including when it is moving upright or when it is moving in a turning state, and it is possible to prevent an erroneous determination that the vehicle has overturned while it is moving. For example, even if the amount of rocking of the rocking body of the first sensor becomes large when the vehicle is moving straight on an uneven road or when it is moving in a turning state, it is possible to prevent an erroneous determination that the vehicle has overturned.

[0202] For example, when a vehicle is traveling straight, the vehicle is upright and no lateral forces are generated. For example, when a vehicle is making a steady turn, the lateral forces caused by centrifugal force are balanced with the lateral forces caused by gravity due to the vehicle's tilt. By basing the detection on the forces applied to the vehicle in this way, it is possible to prevent erroneous determination of a rollover state by the first sensor while the vehicle is traveling straight or making a steady turn, and to improve the accuracy of determining whether the vehicle has rolled over.

[0203] In any of the first to fifth aspects above, in a fall determination method according to a sixth aspect of the present disclosure, the one or more second sensors may include a wheel speed sensor that detects the rotational speed of a non-driven wheel of the vehicle or a difference in rotational speed between a driven wheel and the non-driven wheel of the vehicle, and the fall determination method may include correcting the fall condition based on the detection result of the wheel speed sensor.

[0204] According to the sixth aspect, by detecting the rotation speed of the non-driven wheels or the difference in rotation speed between the driven wheels and the non-driven wheels, it is possible to estimate whether the vehicle is continuing to move, and the tipping condition is corrected according to the estimation result. This makes it possible to estimate the state of continued movement, including the rotation states of the non-driven wheels and the driven wheels due to movement, and prevents erroneous determination that a moving vehicle has tipped over. For example, even if the amount of rocking of the rocking body of the first sensor becomes large when the vehicle is moving straight on an uneven road or when the vehicle is moving in a turning state, it is possible to prevent erroneous determination that the vehicle has tipped over.

[0205] In any of the above first to sixth aspects, the fall determination method according to a seventh aspect of the present disclosure further includes determining whether the movement speed of the vehicle is less than a predetermined set speed based on the detection results of the one or more second sensors, and by correcting the fall condition, the fall condition may be corrected so that when it is determined that the movement speed of the vehicle is less than the set speed, it is more likely that the vehicle has fallen than when the movement speed of the vehicle is equal to or greater than the set speed.

[0206] According to the seventh aspect, when the vehicle is stopped or moving slowly and the moving speed of the vehicle is less than the set speed, it is possible to more easily determine that the vehicle is in an overturned state based on the detection result by the first sensor, thereby preventing a delay in determining that the vehicle is in an overturned state when the vehicle is stopped or moving slowly.

[0207] In any of the above first to seventh aspects, a fall determination method according to an eighth aspect of the present disclosure may further include determining whether or not the detection result of the second sensor is an abnormal value that exceeds a predetermined normal range, and, if the detection result of the second sensor is the abnormal value, disabling correction of the fall condition based on the detection result of the second sensor.

[0208] According to the eighth aspect, correction of the toppling condition can be disabled in an unintended situation such as an abnormality in the second sensor, and a decrease in the accuracy of determination due to the use of the second sensor can be prevented.

[0209] In any of the first to eighth aspects described above, a fall determination method according to a ninth aspect of the present disclosure may include correcting the fall condition based on detection results of the plurality of second sensors.

[0210] According to the ninth aspect, the detection results of a plurality of second sensors are used, so that the accuracy of correction of the toppling condition can be improved, thereby improving the accuracy of determining whether or not a toppling has occurred.

[0211] In any of the above first to ninth aspects, in a fall determination method according to a tenth aspect of the present disclosure, when the detection result by the second sensor continues for a predetermined period, the fall condition may be corrected based on the detection result of the second sensor.

[0212] According to the tenth aspect, when the detection results of the second sensor are acquired over a predetermined period, the overturn condition is corrected based on such detection results. Therefore, the overturn condition is not changed in response to each instantaneous change in the state of the vehicle, and it is possible to stably determine whether the vehicle will overturn.

[0213] In any of the above first to tenth aspects, in a fall determination method according to an eleventh aspect of the present disclosure, the second sensor includes a wheel speed sensor that detects the rotational speeds of drive wheels and non-drive wheels equipped on the vehicle, the drive wheels are wheels to which driving force generated by a prime mover equipped on the vehicle is transmitted, and the non-drive wheels are wheels to which the driving force is not transmitted, and the fall determination method may correct the fall condition so that the fall condition is more difficult to satisfy as a slip ratio, which is the ratio of the difference between the rotational speed of the non-drive wheels and the rotational speed of the drive wheels to the rotational speed of the drive wheels, increases.

[0214] According to the eleventh aspect, the slip ratio can indicate the difference in behavior between the drive wheels and the non-drive wheels, reflecting the influence of the rotational speed of the drive wheels. For example, when the rotational speed of the drive wheels is high, the slip ratio may be small even if the difference between the rotational speed of the drive wheels and the rotational speed of the non-drive wheels is large, which may indicate that the vehicle has rolled over. This improves the accuracy of determining whether the vehicle has rolled over.

[0215] In the above eleventh aspect, in a fall determination method according to a twelfth aspect of the present disclosure, the second sensor may include a speed sensor that detects the speed of the vehicle, and the fall determination method may disable the correction of the fall condition based on the slip ratio when the speed of the vehicle falls below a threshold speed.

[0216] According to the twelfth aspect, the vehicle can travel without tipping over at speeds below the threshold speed even if the slip ratio is large. For example, when the vehicle is traveling in a steady circle, the speed falls below the threshold speed and the slip ratio increases, but the vehicle can continue traveling. This improves the accuracy of determining whether the vehicle has tipped over.

[0217] In any of the above first to twelfth aspects, in a fall determination method according to a thirteenth aspect of the present disclosure, the fall condition is that the amount of tilt of the vehicle from an upright state based on the detection result of the first sensor is equal to or greater than a tilt threshold value, and the fall determination method may correct the fall condition to be more difficult or easier to satisfy by lengthening or shortening the threshold period depending on the detection result of the second sensor.

[0218] According to the thirteenth aspect, the correction of the toppling condition and the determination of whether or not the toppling condition is satisfied are simplified.

[0219] In any of the first to thirteenth aspects described above, a fall determination method according to a fourteenth aspect of the present disclosure may apply, when the state of the vehicle detected by the second sensor satisfies a predetermined state, a reference condition that is preset as the fall condition to the fall condition, and, when the state of the vehicle detected by the second sensor does not satisfy the predetermined state, apply, to the fall condition, a corrected condition obtained by correcting the reference condition so that the reference condition becomes more difficult or easier to satisfy depending on the detection result of the second sensor.

[0220] According to the above-described fourteenth aspect, the toppling condition is corrected by correcting the preset reference condition in accordance with the detection result of the second sensor. Therefore, the correction of the toppling condition is simplified. For example, the reference condition may be the initial setting value of the sway threshold.

[0221] A vehicle according to a fifteenth aspect of the present disclosure comprises a prime mover, a drive structure to which the driving force generated by the prime mover is transmitted and which operates using the driving force to move the vehicle, a first sensor that detects the attitude of the vehicle, one or more second sensors that detect a state of the vehicle different from the first sensor, and a control circuit that controls the prime mover, and the control circuit stops the prime mover when it determines that the vehicle has overturned based on the detection results of both the first sensor and the second sensor.

[0222] According to the fifteenth aspect, the control circuit determines whether the vehicle has overturned using two different sensors that detect different objects. As a result, compared to when the detection result of a single sensor is used to determine whether the vehicle has overturned, the determination result of whether the vehicle has overturned based on the detection result of one sensor can be supplemented by the detection result of the other sensor. Therefore, the accuracy of determining whether the vehicle has overturned can be improved.

[0223] A processing circuit according to a sixteenth aspect of the present disclosure is configured to acquire a detection result from a first sensor that detects the amount of swing of a swinging body that swings in accordance with the posture of the vehicle; acquire a detection result from one or more second sensors that, separate from the first sensor, detects estimated information for estimating the state of the vehicle; determine whether the amount of swing of the swinging body satisfies a predetermined overturning condition based on the detection result of the first sensor; determine that the vehicle has overturned if it is determined that the amount of swing of the swinging body satisfies the overturning condition; and correct the overturning condition based on the detection result of the second sensor.

[0224] According to the sixteenth aspect, the processing circuit can achieve the same effects as the fall determination method according to each aspect of the present disclosure.

[0225] The present disclosure may also be a computer program causing a computer to execute a rollover determination method according to each aspect of the present disclosure. For example, a computer program according to a seventeenth aspect of the present disclosure causes a computer to acquire a detection result from a first sensor that detects a swing amount of a rocking body that rocks in accordance with the attitude of a vehicle, acquire detection results from one or more second sensors that detect, separately from the first sensor, estimated information for estimating a state of the vehicle, determine whether the swing amount of the rocking body satisfies a predetermined rollover condition based on the detection result of the first sensor, determine that the vehicle has rolled over if it is determined that the swing amount of the rocking body satisfies the rollover condition, and correct the rollover condition based on the detection result of the second sensor.

[0226] Such a computer program can achieve the same effects as the fall detection method according to each aspect of the present disclosure. The computer program may be, for example, a program recorded on a non-transitory, tangible, computer-readable recording medium, and may be configured to be read from the recording medium using a recording medium drive device and installed on a computer. The computer program may be, for example, a program that can be distributed via a transmission medium such as the Internet, and may be configured to be downloaded and installed on a computer.

[0227] The functions of the elements disclosed herein can be performed using circuits or processing circuitry, including general-purpose processors, special-purpose processors, integrated circuits, ASICs, conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuitry because it includes transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

[0228] All numbers such as ordinal numbers and quantities used in this specification are provided as examples to specifically explain the technology of the present disclosure, and the present disclosure is not limited to the illustrated numbers. The connection relationships between components are provided as examples to specifically explain the technology of the present disclosure, and the connection relationships that realize the functions of the present disclosure are not limited to these.

[0229] Because the present disclosure may be embodied in various forms without departing from the scope of its essential characteristics, the scope of the present disclosure is defined by the appended claims rather than the description in the specification, and therefore the exemplary embodiments and modifications are intended to be illustrative and not limiting. All modifications that are within the scope of the claims, or equivalents thereof, are intended to be embraced by the claims. [Explanation of symbols]

[0230] 1. Vehicles 10 Drive structure 11a Drive wheels, rear wheels 11b Non-driving wheels, front wheels 20 Prime Mover 40 Processing circuit 50 First sensor, fall sensor 51 Oscillator 60 Second sensor 61 Inertial force sensor (second sensor) 62 Wheel speed sensor (second sensor) 621 Driven wheel speed sensor (second sensor) 622 Drive wheel speed sensor (second sensor) 63, 64 Stroke sensor (second sensor) 65, 66 Air pressure sensor (second sensor)

Claims

1. acquiring a detection result from a first sensor that detects a swing amount of a swinging body that swings in response to a change in attitude of the vehicle; acquiring detection results from one or more second sensors that detect inferred information for estimating the state of the vehicle, separately from the first sensor; determining that the vehicle has overturned when the amount of rocking of the rocking body satisfies a predetermined overturning condition based on the detection result of the first sensor; and correcting the fall condition based on the detection result of the second sensor.

2. The one or more second sensors include sensors used to control the behavior of the vehicle while it is moving. The method for determining a fall according to claim 1 .

3. The one or more second sensors include a sensor for estimating the upright state of the vehicle while it is moving. The method for determining a fall according to claim 1 .

4. and estimating, based on the detection results of the one or more second sensors, whether or not the vehicle is continuing to move due to rotation of drive wheels that rotate by the transmitted drive force to move the vehicle, By correcting the overturn condition, when it is estimated that the movement of the vehicle is continuing due to the rotation of the drive wheels, the overturn condition is corrected so that it becomes more difficult to determine that the vehicle has overturned compared to a state in which the movement of the vehicle is not continuing due to the rotation of the drive wheels. The method for determining a fall according to claim 1 .

5. the vehicle is a lean vehicle that leans when turning, the one or more second sensors include an inertial force sensor that detects a force applied to the vehicle or an attitude of the vehicle; The method for determining a fall includes correcting the fall condition based on a detection result of the inertial force sensor. The method for determining a fall according to claim 1 .

6. the one or more second sensors include a wheel speed sensor that detects a rotation speed of a non-driven wheel of the vehicle or a difference in rotation speed between a driven wheel and the non-driven wheel of the vehicle; The method for determining whether a vehicle will fall includes correcting the conditions for falling based on the detection results of the wheel speed sensors. The method for determining a fall according to claim 1 .

7. The method further includes determining whether a moving speed of the vehicle is less than a predetermined set speed based on the detection results of the one or more second sensors; By correcting the overturn condition, when it is determined that the moving speed of the vehicle is less than the set speed, the overturn condition is corrected so that it is more likely to be determined that the vehicle has overturned than when the moving speed of the vehicle is equal to or greater than the set speed. The method for determining a fall according to claim 1 .

8. determining whether the detection result of the second sensor is an abnormal value that exceeds a predetermined normal range; and when the detection result of the second sensor is the abnormal value, invalidating the correction of the toppling condition based on the detection result of the second sensor. The method for determining a fall according to claim 1 or 2.

9. and correcting the toppling condition based on the detection results of the plurality of second sensors. The method for determining a fall according to claim 1 .

10. When the detection result by the second sensor continues for a predetermined period, the toppling condition is corrected based on the detection result of the second sensor. The method for determining a fall according to claim 1 .

11. A vehicle, The prime mover and a drive structure to which a driving force generated by the prime mover is transmitted, the drive structure being operated by the driving force to move the vehicle; a first sensor for detecting the attitude of the vehicle; one or more second sensors that detect a vehicle condition different from the first sensor; a control circuit for controlling the prime mover, When the control circuit determines that the vehicle has turned over based on the detection results of both the first sensor and the second sensor, it stops the prime mover. vehicle.

Images