JP2007106207A - Rolling speed detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling speed detection device capable of detecting rolling speed while restraining increase of the number of parts. <P>SOLUTION: A wheel speed sensor 25 to detect wheel speed by supporting a wheel 15 which a vehicle 1 has free to revolve around an instant center as seen at a side surface of the vehicle 1 by a suspension device 20 is provided. The wheel speed sensor 25 is connected to a control part 30 doubly working as a rolling speed detection means, and the wheel speed detected by the wheel speed sensor 25 is transmitted to the control part 30. Additionally, rolling angular speed ψ of the car body 5 is detected in accordance with a product of distance L to a grounding point of a wheel 15 from the instant center and a wheel speed differential dv of the left and right wheels 15 in the cross direction of a car body and a tread td of the wheel 15. Consequently, only the wheel speed sensor 25 is sufficient as a detection means of motion of the vehicle 1 and it is possible to restrain increase of the number of the parts. Accordingly, it is possible to detect the rolling speed while restraining increase of the number of the parts. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a roll speed detection device. In particular, the present invention relates to a roll speed detection device capable of simplifying the configuration.

  Some conventional vehicles detect the traveling state of the vehicle and appropriately change the characteristics of the suspension means according to the detected traveling state in order to improve riding comfort and handling stability during vehicle traveling. . Further, when detecting the traveling state in this way, there is one that detects the roll speed as one of the traveling states. For example, in Patent Document 1, a stroke sensor is provided in a shock absorber, and the stroke speed of both shock absorbers in the left-right direction of the vehicle body is detected by the stroke sensor. Further, the roll speed is obtained from the difference between the detected stroke speeds of both shock absorbers, and the damping characteristics of the shock absorber are controlled based on the roll speed. As a result, it is possible to improve ride comfort and steering stability during vehicle travel.

JP-A-6-87315

  However, as described above, a sensor such as a stroke sensor or an acceleration sensor is required when the stroke speed of both shock absorbers in the left-right direction is detected and the roll speed is obtained from the difference in stroke speed. Although the roll speed can be directly grasped, in this case, a rate gyro is required, and in any case, a gyro and a sensor for detecting the roll speed are required. For this reason, when providing the roll speed detection apparatus which detects a roll speed in a vehicle, there existed a possibility that the number of parts might increase.

  This invention is made in view of the above, Comprising: It aims at providing the roll speed detection apparatus which can detect roll speed, suppressing the increase in a number of parts.

  In order to solve the above-described problems and achieve the object, a roll speed detection device according to the present invention includes a wheel speed detection unit that detects a wheel speed that is a rolling speed of a wheel provided in a vehicle, and the vehicle. And a suspension means for rotatably supporting the wheel, the distance from the instantaneous center, which is the center of the rotation in a side view of the vehicle, to the ground contact point of the wheel and the left and right in the width direction of the vehicle Roll speed detecting means for detecting a roll speed of the vehicle body based on a product of the wheel speed difference of the wheel and a tread of the wheel.

  In the present invention, roll speed detection means is provided, and by this roll speed detection means, the product of the distance from the instantaneous center of the suspension means to the wheel contact point and the wheel speed difference between the left and right wheels in the vehicle width direction is calculated. The roll speed is detected based on the tread. In addition, the wheel speed detecting means for detecting the wheel speed is newly used for a roll speed detecting device by using an ABS (Antilock Brake System) which is a vehicle brake control system. The wheel speed can be detected without providing the wheel speed detecting means. As a result, it is possible to detect the roll speed while suppressing an increase in the number of parts.

  Further, in the roll speed detection device according to the present invention, the roll speed detection means detects the wheel speed of any one of the wheels among the wheel speeds of the left and right wheels in the width direction of the vehicle. A wheel speed change speed that is a change speed of the wheel speed is derived, and the wheel speed difference is derived by doubling the wheel speed change speed.

  In this invention, when detecting the roll speed, the wheel speeds of the left and right wheels are determined by detecting the wheel speed of one of the left and right wheels in the width direction of the vehicle and obtaining the wheel speed change speed. The roll speed is detected. That is, when the vehicle body rolls, one of the left and right wheels rotates around the instantaneous center so that it moves upward, and the other wheel moves around the instantaneous center so that it moves downward. Rotate. When the wheel rotates about the center of the moment, it moves upward or downward and at the same time in the longitudinal direction of the vehicle. The movement in the longitudinal direction is opposite between the upward movement and the downward movement. Become a direction. For this reason, the wheel speed of one wheel is detected, the wheel speed change speed of the wheel is obtained from this wheel speed, and the wheel speed difference between the left and right wheels can be easily determined by doubling the wheel speed change speed. Can be sought. As a result, the roll speed can be detected more easily.

  Moreover, the roll speed detection device according to the present invention is characterized in that the wheel whose wheel speed is detected is a driven wheel when the vehicle is traveling.

  In the present invention, the roll speed is detected by detecting the wheel speed of the driven wheel. Since the driving force does not act on the driven wheel when the vehicle travels, the wheel rolls according to the speed difference between the wheel and the road surface. For this reason, the wheel speed difference between the left and right driven wheels in the width direction of the vehicle body is more accurately the wheel speed difference when the vehicle body rolls during vehicle travel. Therefore, when detecting the wheel speed difference between the left and right wheels, the wheel speed difference can be detected more accurately by detecting the wheel speed of the driven wheel. As a result, the roll speed can be detected more accurately.

  The roll speed detection device according to the present invention has an effect that the roll speed can be detected while suppressing an increase in the number of parts.

  Hereinafter, an embodiment of a roll speed detection device according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  In the following description, the vertical direction indicates the vertical direction in the traveling state of the vehicle, that is, the direction in which gravity acts, the lower direction indicates the direction in which gravity acts, and the upper direction in the direction in which gravity acts. The opposite direction is shown. FIG. 1 is a schematic view of a vehicle including a roll speed detection device according to an embodiment of the present invention. The vehicle 1 shown in FIG. 1 has wheels 15 that roll on the road surface when the vehicle 1 travels. The wheels 15 are provided at four locations so as to be arranged in the left-right direction and the front-rear direction of the vehicle body 5 of the vehicle 1. These four wheels 15 are attached to the vehicle body 5 by a suspension device 20 which is a suspension means. This suspension device 20 is provided so that the four wheels 15 can move independently in a substantially vertical direction, and a shock absorber 21 that can extend and contract in a substantially vertical direction is provided in the vicinity of each wheel 15. . The suspension device 20 includes the shock absorber 21 and arms (not shown) that connect the vehicle body 5 and the wheels 15. Each of these wheels 15 is rotatable about a rotation axis (not shown). Of the four wheels 15 that can rotate in this manner, the two front wheels 15, that is, the front wheels 16, are driving wheels that are driven when the vehicle 1 travels. The two wheels 15, that is, the rear wheel 17, are driven wheels that roll according to the speed difference between the rear wheel 17 and the road surface.

  Further, a brake unit (not shown) is provided in a portion closer to the rotation axis of the wheel 15 than the outer peripheral portion of each of the four wheels 15. This brake unit is provided with an ABS (not shown) that is a brake control system for controlling braking of the vehicle 1, and a wheel that is a part of the ABS and is a wheel speed detection means in the vicinity of the rotating shaft of the wheel 15. A speed sensor 25 is provided. The wheel speed sensors 25 are provided on all the wheels 15 and are provided so as to detect the wheel speed that is the rolling speed of each wheel 15.

  Further, the wheel speed sensor 25 is connected to a control unit 30 composed of an ECU (Electronic Control Unit) that controls each part of the vehicle 1. The control unit 30 is also provided as a roll speed detection unit that detects the roll speed of the vehicle body 5, and the wheel speed detected by the wheel speed sensor 25 is transmitted to the control unit 30. Further, the wheel speed sensor 25 and the control unit 30 provided in the vehicle 1 constitute a roll speed detection device 10.

  The control unit 30 including an ECU is provided with a storage unit (not shown) and a processing unit (not shown). Among these, the storage unit stores a computer program for controlling the roll speed detection device 10 according to the present invention. This storage unit is a hard disk device, a magneto-optical disk device, a non-volatile memory such as a flash memory (a storage medium that can be read only such as a CD-ROM), or a volatile memory such as a RAM (Random Access Memory). The memory can be configured by a combination of these, or a combination thereof.

  The processing unit includes a memory (not shown) and a CPU (Central Processing Unit). The roll speed of the vehicle body 5 is detected by the roll speed detection device 10 based on the wheel speed transmitted from the wheel speed sensor 25, and the processing unit reads the computer program into a memory incorporated in the processing unit and performs calculation. . At that time, the processing unit appropriately stores a numerical value in the middle of the calculation in the storage unit, and retrieves the stored numerical value and executes the calculation. In addition, when controlling the roll speed detection apparatus 10 in this way, you may control by the dedicated hardware different from ECU instead of the said computer program.

  The roll speed detection device 10 according to this embodiment is configured as described above, and the operation thereof will be described below. When the vehicle 1 travels, a force generated by an internal combustion engine (not shown) mounted on the vehicle 1 is transmitted to the front wheel 16 that is a drive wheel, and the front wheel 16 rolls about the rotation axis. Thereby, the vehicle 1 whole moves. Further, when the vehicle 1 moves, the rear wheel 17 that is a driven wheel also moves, and the rear wheel 17 rolls about the rotation axis by the frictional force between the outer peripheral surface and the road surface. For this reason, all four wheels 15 roll while the vehicle 1 is traveling.

  In addition, when braking is performed while the vehicle 1 is traveling, the brake unit is activated so that the wheel speed of the wheel 15 is reduced. The wheel speed of the wheel 15 is always transmitted to the control unit 30 when the vehicle 1 is traveling. Accordingly, when the vehicle 1 is strongly braked or when the vehicle 1 is braked on a road surface having a low coefficient of friction, the vehicle 15 is not stopped but the rotation of the wheels 15 is stopped. When the wheel speed sensor 25 detects, the ABS is activated. That is, the operation of the brake unit provided on the wheel 15 whose rotation is stopped is reduced, the rotation of the wheel 15 whose rotation is stopped is recovered, and the brake unit is operated again to generate the braking force.

  FIG. 2 is an outline view showing a state where the vehicle body is rolling. Further, the vehicle 1 is provided with a suspension device 20 for attaching the wheel 15 to the vehicle body 5, and the suspension device 20 has a shock absorber 21. The shock absorber 21 is provided so as to be extendable and contractible in the length direction, and is most extended when there is no load. When the load is applied in the direction in which the shock absorber 21 is contracted, the length is shortened according to the load. Since the shock absorber 21 expands and contracts according to the load, the wheel 15 attached to the vehicle body 5 by the suspension device 20 having the shock absorber 21 can move substantially vertically according to the expansion and contraction of the shock absorber 21. Yes. That is, when no load is applied to the wheel 15, the shock absorber 21 is in an extended state, and when a load is applied in a direction that causes the wheel 15 to be directed upward or the vehicle body 5 to be directed downward, Depending on the load, the wheel 15 moves upward or the vehicle body 5 sinks.

  Further, the vehicle 1 performs straight traveling and cornering during traveling. When the vehicle travels straight on a flat road at a constant speed, the load acting on the wheels 15 is constant, so the relative positional relationship between the vehicle body 5 and the wheels 15 does not change much.

  On the other hand, when cornering is performed while the vehicle 1 is traveling, the center of gravity of the vehicle 1 moves toward the outside of the cornering. For this reason, a load larger than the load acting during the straight traveling is applied to the wheel 15 located in the outer direction of the cornering, and the load acting during the straight traveling is smaller than the load acting during the straight traveling. A load acts. As a result, the length of the shock absorber 21 positioned in the outer direction of the cornering is shorter than that when the vehicle 1 is traveling straight, and the length of the shock absorber 21 positioned in the inner direction of the cornering is longer than that when the vehicle 1 is traveling straight. Become. Accordingly, in the vehicle body 5 during cornering, the portion positioned in the outer direction of the cornering sinks, the entire vehicle body 5 is tilted in the direction in which the portion positioned in the inner direction of the cornering is lifted, and the vehicle body 5 rolls.

  FIG. 3 is an explanatory side view showing a state of movement of the front wheels when the vehicle body is rolled. FIG. 4 is an explanatory side view showing a state of movement of the rear wheels when the vehicle body is rolled. Since the wheel 15 is attached to the vehicle body 5 so that it can be moved substantially vertically by the suspension device 20, when the vehicle body 5 rolls, the wheel 15 moves upward or downward. When the vehicle 1 is viewed from the side surface direction or when viewed from the pitch axis direction of the vehicle 1, that is, by rotating about the instantaneous center 40 that is the center of rotation in a side view, Move up and down. Further, all of the suspension devices 20 connected to the four wheels 15 are independently provided at the instantaneous center 40, and all the suspension centers 20 are located above the road surface. Further, the instantaneous center 40 of the front wheel 16 is located behind the front wheel 16, and the instantaneous center 40 of the rear wheel 17 is located forward of the rear wheel 17. For this reason, the rear wheel 17 rotates around the instantaneous center 40 located in front of the rear wheel 17. In other words, the suspension device 20 attaches the wheel 15 to the vehicle body 5 and supports the wheel 15 so as to be rotatable about the instantaneous center 40 in a side view of the vehicle 1.

  While the vehicle 1 is traveling, the wheel 15 is in contact with the road surface, but the contact point 45, which is a portion where the wheel 15 is in contact with the road surface, is located below the instantaneous center 40. That is, the instantaneous center 40 is located above the road surface and located above the ground contact point 45. For this reason, when the rear wheel 17 in which the instantaneous center 40 is located in front of the wheel 15 is described, the shock absorber 21 is contracted, the rear wheel 17 is moved upward, or the vehicle body 5 is depressed, that is, bounces. When the rear wheel 17 rotates about the instantaneous center 40, the ground contact point 45 moves backward. On the contrary, when the shock absorber 21 is extended and the rear wheel 17 is moved downward or the vehicle body 5 is lifted, that is, when it is rebounded, when the rear wheel 17 rotates around the instantaneous center 40, the ground contact point 45 moves forward. Further, when the front wheel 16 where the instantaneous center 40 is located behind the wheel 15 bounces, when the front wheel 16 rotates around the instantaneous center 40, the ground contact point 45 moves forward and rebounds. In this case, when the front wheel 16 rotates around the instantaneous center 40, the ground contact point 45 moves backward.

  Moreover, when the vehicle body 5 rolls, the wheel 15 located on one side of the wheels 15 located on the left and right in the width direction of the vehicle 1 or the vehicle body 5 bounces, and the wheel 15 located on the other side Rebound. For this reason, on the side where the vehicle body 5 sinks during rolling, that is, on the bounce side, the ground contact point 45 of the front wheel 16 moves forward, and the ground contact point 45 of the rear wheel 17 moves rearward. Conversely, on the side where the vehicle body 5 is lifted during rolling, that is, on the rebound side, the ground contact point 45 of the front wheel 16 moves rearward, and the ground contact point 45 of the rear wheel 17 moves forward.

  FIG. 5 is an explanatory diagram showing the positional relationship between the instantaneous center and the ground point in FIG. The positional relationship and movement between the instantaneous center 40 and the grounding point 45 when the rear wheel 17 bounces will be described in detail. The distance from the instantaneous center 40 to the grounding point 45 is L, and the rear wheel 17 is centered on the instantaneous center 40. Assuming that the angular velocity at the time of rotation is θ, the vertical stroke speed that is the substantially vertical movement speed of the ground contact point 45 at the time of bouncing is Lθ.

  Further, when the rear wheel 17 bounces, the ground contact point 45 moves from the front to the rear. However, considering that the rear wheel 17 moves upward during the bounce, the pre-bounding ground contact point 46 and the post-bounding ground contact point 47 are moved. The triangle whose vertex is at each position with the ground point 48 is substantially similar to the triangle whose vertex is at each position of the instantaneous center 40, the pre-bounding ground point 46 and the post-bounding ground point 47. Note that the pre-bounding contact point 46 of the rear wheel 17 is a contact point before the rear wheel 17 bounces, and the post-bounding contact point 47 of the rear wheel 17 is a contact point after the rear wheel 17 bounces. The post-movement grounding point 48 of the rear wheel 17 is a position corresponding to the post-bounding grounding point 47 whose vertical position is the same as the vertical position of the pre-bounding grounding point 46.

  For this reason, the angle of the instantaneous center corner 50, which is a corner formed by the side extending to the pre-bounding contact point 46 and the side extending to the post-bounding contact point 47 with the instantaneous center 40 as the apex, is the post-bounding contact point 47. The angle of the post-bounding contact point corner 51, which is a corner formed by the side extending to the pre-bounding contact point 46 and the side extending to the post-movement contact point 48, is approximately the same. . As a result, the rear wheel 17 bounces, the angular speed θ of the instantaneous central corner 50 when the grounding point 45 moves from the pre-bounding grounding point 46 to the post-bounding grounding point 47 around the instantaneous center 40, and the pre-bounding grounding point. Both the angular velocities θ of the after-bounding contact point corner 51 when moving from 46 to the contact point 48 after movement are the same.

Further, since the vertical stroke speed from the pre-bounding contact point 46 to the post-bounding contact point 47 at the time of bouncing is Lθ, the speed from the pre-bounding contact point 46 to the post-movement contact point 48, that is, the rear wheel 17. There longitudinal moving speed of the ground contact point 45 at the time of bounces will Lθ ^2. When the rear wheel 17 bounces, the ground contact point 45 between the rear wheel 17 and the road surface moves at a predetermined speed in the front-rear direction as described above. However, while the vehicle 1 is traveling, the rear wheel 17 moves at the speed of the vehicle 1. Rolling at wheel speeds according to When the rear wheel 17 does not bounce or rebound, the wheel speed becomes the speed according to the speed of the vehicle 1. However, when the rear wheel 17 bounces, the ground contact point 45 moves in the front-rear direction when the rear wheel 17 bounces. Therefore, the speed of the rear wheel 17 at the time of bouncing moves at a speed slightly different from the speed of the vehicle 1. For this reason, the wheel speed is also different from the case where the rear wheel 17 is not bouncing. Accordingly, the moving speed Lθ ² from the pre-bounding contact point 46 to the post-moving contact point 48 becomes the wheel speed change speed Lθ ² that is the change speed of the wheel speed of the rear wheel 17 at the time of the bouncing.

  Further, when the rear wheel 17 bounces, the rear wheel 17 rotates about the instantaneous center 40 so that the ground contact point moves from below to above when viewed from the instantaneous center 40 as described above. However, when the rear wheel 17 rebounds, on the contrary, the rear wheel 17 is centered on the instantaneous center 40 so that the ground contact point 45 moves downward from above when viewed from the instantaneous center 40. Rotate. For this reason, when the rear wheel 17 rebounds, the ground contact point 45 moves from the rear to the front, contrary to the bounding time.

Here, when the vehicle body 5 rolls, the wheel 15 located on the left and right in the width direction of the vehicle 1, that is, the wheel 15 on one side of the left and right wheels bounces, while the wheel 15 on the opposite side rebounds. The stroke amount in the vertical direction is substantially the same, and the stroke direction is reversed. For this reason, the left and right wheels 15 at the time of rolling are of the same size and move in the front-rear direction so that the directions in the front-rear direction are opposite to each other. Thereby, the change of the wheel speed of the left and right wheels 15 at the time of rolling is substantially the same as the speed change with respect to the wheel speed before the roll, and the direction of the speed change is opposite to each other. For this reason, the wheel speed difference between the left and right wheels when the vehicle body 5 is rolled is twice the wheel speed change speed of one wheel 15 of the left and right wheels when rolling. That is, in the rear wheel 17 described above, the wheel speed change speed at the time of bouncing is Lθ ² , so the wheel speed difference between the left and right wheels of the rear wheel 17 is twice Lθ ² , and the wheel speed difference between the left and right wheels. dv can be expressed as in the following formula (1).
dv = 2Lθ ² (1)

  FIG. 6 is a view taken along the line AA in FIG. 4 and is an explanatory diagram illustrating a state of change of the left and right wheels during the roll. Further, when the vehicle body 5 rolls, one of the left and right wheels bounces and the other rebounds, but the vertical stroke speed at the time of bounce and rebound is both Lθ, and the directions of movement are opposite to each other. . For this reason, the speed difference between the vertical stroke speeds of the left and right wheels is twice the speed difference of the vertical stroke speed of one of the left and right wheels 15, and the speed difference of the vertical stroke speeds of the left and right wheels is 2Lθ. It becomes.

In addition, since the roll of the vehicle body 5 is generated when one of the left and right wheels bounces and the other rebounds, in other words, when one wheel 15 of the left and right wheels is used as a reference, This is equivalent to the wheel 15 stroked in the vertical direction at a speed of 2Lθ. For this reason, the roll angular velocity φ of the vehicle body 5 is expressed by the following equation (2) by setting td as the distance between the left and right wheels in the width direction of the vehicle 1 as td with reference to one wheel 15 of the left and right wheels. Can be expressed as:
φ = (2Lθ) / td (2)

For this reason, roll angular velocity (phi) can be represented like following formula (3) from the said Formula (1) and Formula (2).
φ = (√ (2Ldv)) / td (3)

  Since the roll angular velocity φ of the vehicle body 5 can be expressed in this way, the distance L from the instantaneous center 40 to the ground contact point 45 of the wheel 15 and the tread td of the wheel 15 are stored in the control unit 30 in advance. It is obtained by substituting the wheel speed difference dv between the left and right wheels of the rear wheel 17 into the equation (3).

In other words, the wheel speed of the rear wheel 17 is detected by the wheel speed sensor 25 and transmitted to the control unit 30 while the vehicle 1 is traveling, and is detected by the wheel speed sensor 25 when the wheel speed of the left and right rear wheels 17 changes. The wheel speed difference dv between the left and right wheels is determined by the control unit 30 by doubling the wheel speed change speed Lθ ² of the one rear wheel 17, and the wheel speed difference dv and the ground contact point 45 of the wheel 15 from the instantaneous center 40 are obtained. The roll angular velocity φ is obtained by the control unit 30 by substituting the distance L up to and the tread td of the wheel 15 into the equation (3).

  The roll speed detection device 10 described above includes the product of the distance L from the instantaneous center 40 to the ground contact point 45 of the wheel 15 and the wheel speed difference dv of the left and right wheels 15 in the width direction of the vehicle 1, and the tread td of the wheel 15. , The roll angular velocity φ of the vehicle body 5, that is, the roll velocity is detected by the control unit 30. Among these, the distance L from the instantaneous center 40 to the ground contact point 45 of the wheel 15 and the tread td of the wheel 15 can be known at the design stage of the vehicle 1, and the wheel speed difference dv between the left and right wheels 15 is determined by the vehicle 1. Can be detected by a wheel speed sensor 25 used in an ABS which is a brake control system mounted on the vehicle. Thus, the wheel speed can be detected without providing a new wheel speed detecting means for the roll speed detecting device 10. Therefore, the roll speed can be detected without using a new detection means for the roll speed detection device 10. As a result, the roll speed that is the roll angular speed φ can be detected while suppressing an increase in the number of parts. In addition, since the increase in the number of parts can be suppressed, the manufacturing cost can be reduced.

Further, when the roll angular velocity φ is detected, the wheel speed change speed Lθ ² of one of the left and right wheels 15 is detected, and the wheel speed change speed Lθ ² is doubled to determine the left and right wheels. Is detected by calculating the wheel speed difference dv. That is, when the vehicle body 5 rolls, one wheel 15 of the left and right wheels rotates around the instantaneous center 40 so as to move upward, and the other wheel 15 moves so as to move downward. Rotate around 40. When the wheel 15 rotates about the instantaneous center 40, the wheel 15 moves upward or downward and simultaneously moves in the front-rear direction of the vehicle 1, and moves in the front-rear direction depending on whether it moves upward or downward. Are in opposite directions.

Here, the roll angular velocity φ is the product of the distance L from the instantaneous center 40 of the suspension device 20 that supports one of the left and right wheels 15 to the ground contact point 45 of the wheel 15 and the wheel speed change speed Lθ ^2. by doubling, calculated wheel speed change rate Erushita ² of the left and right wheels 15 by the wheel speed sensor 25 provided on the left and right wheels 15, from wheel speed change rate Erushita ² of the left and right wheels, wheel speeds of these wheels 15 The difference dv is obtained, and further obtained from the product of the wheel speed difference dv and the distance L from the instantaneous center 40 to the ground contact point 45 of the wheel 15 and the tread td of the wheel 15. On the other hand, the wheel speed change speed Lθ ² of one wheel 15 out of the wheel speeds of the left and right wheels 15 is detected to determine the wheel speed difference dv between the left and right wheels, and from this wheel speed difference dv and the instantaneous center 40 By determining the roll angular velocity φ from the distance L to the ground contact point 45 of the wheel 15 and the tread td of the wheel 15, the wheel speed change speed Lθ ² of both the left and right wheels 15 is detected as described above. A result equivalent to that obtained when the roll angular velocity φ is obtained can be obtained. As a result, the roll speed can be detected more easily.

  Further, the roll speed detecting device 10 detects the roll angular speed φ by detecting the wheel speed of the rear wheel 17 that is a driven wheel. Since the driving force does not act on the driven wheel when the vehicle travels, the wheel 15 rolls according to the speed difference between the wheel 15 and the road surface. For this reason, the wheel speed difference dv between the left and right driven wheels in the width direction of the vehicle 1 more accurately is the wheel speed generated due to the rotation of the wheel 15 about the instantaneous center 40 when the vehicle body 5 is rolled. The difference is dv. Therefore, when the wheel speed difference dv between the left and right wheels 15 is detected, the wheel speed difference dv between the left and right wheels at the time of rolling is detected more accurately by detecting the wheel speed of the rear wheel 17 that is a driven wheel. Can do. As a result, the roll angular velocity φ can be detected more accurately, and the roll speed can be detected.

FIG. 7 is an explanatory diagram illustrating a modification of the roll speed detection device according to the embodiment. In the above description, the wheel speed change speed Lθ ² is detected by detecting the wheel speed of the rear wheel 17 and the roll angular speed φ is obtained as it is. However, when the roll angular speed φ is obtained, it may be corrected. Good. For example, in the vehicle 1 in which the front wheel 16 is a driving wheel and the rear wheel 17 is a driven wheel, when the roll angular velocity φ is obtained by detecting the wheel speed of the rear wheel 17, cornering as shown in FIG. A difference in wheel speed between the wheels, that is, an inner / outer wheel difference occurs. Even in this case, the roll angular velocity φ can be determined more accurately by correcting the difference between the inner and outer rings.

Specifically, when the turning radius, which is the turning radius when cornering the vehicle 1, is R, the tread of the rear wheel 17 is td, the speed of the vehicle 1, that is, the vehicle body speed is V, and the yaw rate is r, Outer wheel speed Vout which is the wheel speed of the outer rear wheel 17out which is the rear wheel 17 which is located on the outer side of the cornering during cornering or the rear wheel 17 on the bounce side is obtained by the following equation (4). be able to.
Vout = (R + (td / 2)) × r = V + (td / 2) × r (4)

  As for the yaw rate r, a yaw rate sensor (not shown) may be provided in the vehicle 1, and the yaw rate r of the running vehicle 1 may be directly measured by the yaw rate sensor, and the steering angle of the steering (not shown), the vehicle speed, etc. It may be estimated from the information.

Similarly, of the left and right rear wheels 17, the inner wheel speed Vin which is the wheel speed of the inner rear wheel 17 in which is the side located in the inner direction of the cornering during cornering or the rear wheel 17 on the rebound side is expressed by the following equation: (5).
Vin = (R− (td / 2)) × r = V− (td / 2) × r (5)

Thus, since the outer wheel speed Vout and the inner wheel speed Vin at the time of cornering of the vehicle 1 can be calculated by the turning radius R and the yaw rate r, the right and left wheel speed difference dv corrected in consideration of these is used. A certain corrected wheel speed difference dv ′ can be obtained by the following equation (6).
dv ′ = dv + (Vout−Vin) = dv + tdr (6)

  As a result, when detecting the roll angular velocity φ of the roll of the vehicle body 5 caused by cornering, the corrected wheel speed difference dv ′ can be obtained in consideration of the inner and outer wheel differences during cornering by including the yaw rate r. By using the speed difference dv ′, the roll angular velocity φ during cornering can be obtained more accurately. As a result, the roll speed can be detected more accurately.

  In the above description, the wheel 15 that detects the wheel speed by the wheel speed sensor 25 is the rear wheel 17 that is a driven wheel, but the wheel 15 that detects the wheel speed may be the front wheel 16 or the front wheel. The wheel speeds of the wheels 15 of both the 16 and the rear wheels 17 may be detected. The vehicle 1 including the roll speed detection device 10 has the front wheel 16 as a driving wheel and the rear wheel 17 as a driven wheel, but the front wheel 16 is a driven wheel and the rear wheel 17 is a driving wheel. Moreover, both the front wheel 16 and the rear wheel 17 may be drive wheels. The wheel 15 for detecting the wheel speed may be any of the front wheel 16 and the rear wheel 17, or the driven wheel and the driving wheel 15. In the case of detecting at the wheel speed of any wheel 15, the roll angular speed φ, that is, the roll speed can be easily detected by detecting the wheel speed difference dv between the left and right wheels having the same position in the front-rear direction. it can.

  Furthermore, the wheel 15 that detects the wheel speed difference dv only needs to be able to detect the wheel speed difference dv between the left and right wheels 15 in the width direction of the vehicle 1, and the left and right wheels 15 are not necessarily in the same position in the front-rear direction of the vehicle 1. It does not have to be. Even between the left and right wheels 15 having different positions in the front-rear direction, when the vehicle body 5 rolls, the wheel speed difference dv is equivalent to the wheels 15 having the same position in the front-rear direction, and from the instantaneous center 40 to the grounding point. If the distance L between the wheels 15 is the same, the roll angular velocity φ, that is, the roll velocity can be easily detected.

  Moreover, when calculating | requiring roll angular velocity (phi) from the detected wheel speed, it is preferable to correct | amend according to the wheel 15 which detected the wheel speed. That is, the wheel speed difference between the left and right wheels may vary depending on whether the front wheel 16 or the rear wheel 17 is a driven wheel or a driving wheel. It is preferable to perform a corresponding correction. As a result, the roll speed can be detected more accurately.

  As described above, the roll speed detection device according to the present invention is useful for detecting the roll speed during vehicle travel, and is particularly suitable for reducing costs.

It is the schematic of a vehicle provided with the roll speed detection apparatus which concerns on the Example of this invention. It is an external view which shows the state which the vehicle body is rolling. It is side view explanatory drawing which shows the state of the movement of the front wheel at the time of the rolling of a vehicle body. It is side view explanatory drawing which shows the state of the movement of the rear-wheel at the time of the rolling of a vehicle body. It is explanatory drawing which shows the positional relationship of the instantaneous center of FIG. 4, and a grounding point. It is an AA arrow line view of FIG. 4, and is explanatory drawing which shows the state of the change of the left-right wheel at the time of a roll. It is explanatory drawing which shows the modification of the roll speed detection apparatus which concerns on an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 5 Car body 10 Roll speed detection apparatus 15 Wheel 16 Front wheel 17 Rear wheel 17in Inner rear wheel 17out Outer rear wheel 20 Suspension device 21 Shock absorber 25 Wheel speed sensor 30 Control part 40 Instantaneous center 45 Ground point 46 Bound before ground point 47 Bound Rear contact point 48 Ground point after moving 50 Instantaneous central corner 51 Ground point after bound

Claims (3)

A wheel speed detecting means for detecting a wheel speed which is a rolling speed of a plurality of wheels provided in the vehicle;
A suspension means provided on the vehicle and rotatably supporting the wheel in a distance from an instantaneous center, which is the center of the rotation in a side view of the vehicle, to a contact point of the wheel and in a width direction of the vehicle A roll speed detecting means for detecting a roll speed of the vehicle body based on a product of the wheel speed difference between the left and right wheels and a tread of the wheel;
A roll speed detecting device comprising:   The roll speed detecting means detects the wheel speed of any one of the wheel speeds of the left and right wheels in the width direction of the vehicle and detects a wheel speed change speed that is a change speed of the wheel speed. The roll speed detection device according to claim 1, wherein the wheel speed difference is derived by deriving the wheel speed change speed and doubling the wheel speed change speed.   The roll speed detection device according to claim 1 or 2, wherein the wheel whose wheel speed is detected is a driven wheel when the vehicle is running.

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