JP2010083370A - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle control device enhancing the fuel economy while ensuring the turning performance of a vehicle. <P>SOLUTION: On a road surface of the low friction coefficient, for example, when the operational angle of a steering 63 is equal to or larger than the predetermined value, the negative camber is given to front wheels 2FL, 2FR forming the outer turning wheel side. In the wheels 2, the ground contact load is increased during the turn, and the turning performance can be efficiently ensured accordingly by increasing the effect of the camber thrust. Meanwhile, if the negative camber is given to each wheel 2, the fuel consumption performance is degraded due to the increase in the rolling resistance of the wheels caused through the camber thrust. Thus, since the negative camber is given only to the wheels 2 (the front wheels 2FL, 2FR forming the outer turning wheel side) capable of efficiently generating the camber thrust, the increase in the rolling resistance is minimized while the turning performance is ensured, and the fuel consumption performance can be enhanced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle control device, and more particularly, to a vehicle control device that can improve fuel efficiency while ensuring turning performance of the vehicle.

Conventionally, an attempt has been made to improve the turning performance of a vehicle by setting a camber angle of a wheel (an angle formed by a wheel center and a traveling road surface) in a negative direction (giving a negative camber). That is, by giving a negative camber to the wheel, the canvas last can be exhibited, and accordingly, the turning performance can be ensured accordingly. Further, even when the vehicle body at the time of turning rolls, it is possible to suppress the camber angle of the turning outer wheel from becoming a positive camber, so that it is possible to secure a gripping force and ensure turning performance (Patent Document 1). ).
Japanese Patent Laid-Open No. 05-065010

  However, in the above-described conventional technology, although the turning performance can be ensured by setting the camber angle in the negative direction, the rolling resistance of the wheel increases due to the canvas last, which causes a reduction in the fuel consumption performance of the vehicle. There was a problem.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle control device that can improve fuel efficiency while ensuring the turning performance of the vehicle.

  In order to achieve this object, the vehicle control apparatus according to claim 1 is a camber angle adjustment that independently adjusts the left and right front wheels and the left and right rear wheels and the camber angles of the left and right front wheels and the left and right rear wheels. A driving state determining means for determining whether or not the vehicle is turning, and whether a friction coefficient of the road surface is lower than a predetermined value. When the road surface state estimation means to be estimated and the road surface state estimation means estimate that the friction coefficient of the road surface is lower than a predetermined value, and the travel state determination means determines that the vehicle is turning Front wheel camber control means for operating the camber angle adjusting device to apply a negative camber to the front wheel on the turning outer wheel side of the left and right front wheels.

  The vehicle control device according to claim 2 is the vehicle control device according to claim 1, wherein a steering angle acquisition unit that acquires a steering angle of the left and right front wheels, a yaw rate acquisition unit that acquires a yaw rate of the vehicle, Turning state determination means for determining whether the steering angle of the left and right front wheels acquired by the steering angle acquisition means is larger than a predetermined value or whether the yaw rate of the vehicle acquired by the yaw rate acquisition means is larger than a predetermined value. The front wheel camber control means determines that the road surface state estimation means estimates that the friction coefficient of the road surface is lower than a predetermined value, and determines that the vehicle is turning by the turning state determination means. Further, the steering angle of the left and right front wheels acquired by the steering angle acquisition unit is greater than a predetermined value by the turning state determination unit, or -When it is determined that the yaw rate of the vehicle acquired by the rate acquisition means is greater than a predetermined value, the camber angle adjusting device is operated to apply a negative camber to the front wheel on the turning outer wheel side of the left and right front wheels. Give.

  A vehicle control device according to claim 3 is the vehicle control device according to claim 1 or 2, wherein a yaw rate reference value storage for storing a reference value of the yaw rate of the vehicle in association with a steering angle of the left and right front wheels. Means corresponding to the steering angles of the left and right front wheels acquired by the steering angle acquisition means, the yaw rate acquisition means for acquiring the yaw rate of the vehicle, and the steering angle acquisition means for acquiring the steering angle of the left and right front wheels. A yaw rate reference value is read from the yaw rate reference value storage means, and the yaw rate determination means for determining whether the yaw rate of the vehicle acquired by the yaw rate acquisition means is smaller than the read yaw rate reference value; and the yaw rate determination means When the yaw rate of the vehicle is determined to be smaller than a reference value of the yaw rate. An integer unit is operated, and a, a rear wheel camber control means after imparting negative camber or positive camber in the rear wheels becomes the turning outer side of the rear wheel of the right and left.

  The vehicle control device according to claim 4 is the vehicle control device according to claim 3, wherein a lateral acceleration reference value storage means for storing a reference value of the lateral acceleration of the vehicle in association with a steering angle of the left and right front wheels. A lateral acceleration acquisition means for acquiring a lateral acceleration of the vehicle; and a reference value of the lateral acceleration corresponding to the steering angle of the left and right front wheels acquired by the steering angle acquisition means is read from the lateral acceleration reference value storage means. Lateral acceleration determination means for determining whether the lateral acceleration of the vehicle acquired by the acquisition means is smaller than the read reference value of the lateral acceleration, and the rear wheel camber control means includes the lateral acceleration determination If it is determined by the means that the lateral acceleration of the vehicle is smaller than the reference value of the lateral acceleration, a positive camber is applied to the rear wheel on the turning outer wheel side of the left and right rear wheels. Rutotomoni, lateral acceleration of the vehicle when it is determined to be larger than the reference value of the lateral acceleration, imparts negative camber in the rear wheels becomes the turning outer side of the rear wheel of the right and left.

  The vehicle control device according to claim 5 is used for a vehicle including left and right front wheels and left and right rear wheels and a camber angle adjusting device that independently adjusts camber angles of the left and right front wheels and left and right rear wheels. A running state judging means for judging whether the vehicle is turning, a road surface state estimating means for estimating whether a friction coefficient of the road surface is lower than a predetermined value, and a yaw rate of the vehicle from a predetermined value. And a yaw rate determination means for determining whether the vehicle is turning. The road condition determination means determines that the vehicle is turning, and the road surface condition estimation means has a friction coefficient of the road surface lower than a predetermined value. The camber angle adjusting device is operated to give a camber angle to at least one of the left and right front wheels, and further, the yaw rate determining means When the yaw rate of the vehicle is determined to be smaller than the predetermined value, they actuate the camber angle adjusting device to impart camber angle to at least one wheel of the rear wheel of the right and left.

  The vehicle control device according to claim 6 is the vehicle control device according to any one of claims 1 to 5, wherein the left and right front wheels and the left and right rear wheels have a first tread, a characteristic of the first tread, and characteristics thereof. And the second tread is configured to have a higher gripping property than the second tread, and the second tread is configured to be higher than the first tread. When the first tread is located on the inner side of the vehicle than the second tread and a negative camber is applied, the ground contact area of the first tread is increased.

  According to the vehicle control device of the first aspect, when the camber angle actuating device is operated, the camber angles of the left and right front wheels and the left and right rear wheels are independently adjusted, and the left and right front wheels or the left and right rear wheels are adjusted. A predetermined camber angle is given to a part or all of.

  Here, according to the vehicle control device of the present invention, when the camber angle adjusting device is operated by the front wheel camber control means, the negative camber is given to the front wheel on the turning outer wheel side of the left and right front wheels. The front wheel on the side of the turning outer wheel exhibits a canvas last, and accordingly, the turning performance can be ensured.

  In particular, according to the vehicle control device of the present invention, the wheel to which the negative camber is applied is the front wheel on the turning outer wheel side, and this is a wheel with a large ground load during turning. Therefore, since the influence of the canvas last can be increased, there is an effect that the turning performance can be efficiently ensured accordingly.

  That is, if a negative camber is applied to all the wheels, the increase in the rolling resistance of the wheels due to the canvas last causes a reduction in fuel consumption performance. As described above, the wheels that can efficiently generate the canvas last (the turning outer wheels) By giving a negative camber only to the front wheels), it is possible to minimize the increase in rolling resistance while ensuring the turning performance, and to improve the fuel efficiency accordingly.

  In addition, for example, if the road surface friction coefficient is relatively high and a grip force can be expected, or if the vehicle is running straight ahead, it is not necessary to improve the turning performance. However, according to the vehicle control device of the present invention, the negative camber is given to the front wheel on the turning outer wheel side in order to estimate the road surface condition. Since it is estimated that the friction coefficient of the road surface is lower than the predetermined value by the means and the vehicle is judged to be turning by the traveling state judging means, it is efficient to ensure turning performance and improve fuel efficiency. Can be compatible.

  According to the vehicle control device of the second aspect, in addition to the effect produced by the vehicle control device according to the first aspect, the road surface state estimating means estimates that the friction coefficient of the road surface is lower than a predetermined value, and turns. The state determination means determines that the vehicle is turning, and the turning state determination means determines that the steering angle of the left and right front wheels acquired by the steering angle acquisition means is greater than a predetermined value or is acquired by the yaw rate acquisition means. When it is determined that the yaw rate of the vehicle is larger than a predetermined value, the camber angle adjusting device is operated by the front wheel camber control means to give a negative camber to the front wheel on the turning outer wheel side of the left and right front wheels. Because of its construction, the canvas last ensures the turning performance while suppressing the increase in rolling resistance due to unnecessary camber angle, resulting in fuel efficiency. There is an effect that it is possible to improve the.

  That is, when the steering angle of the left and right front wheels is smaller than a predetermined value or when the vehicle yaw rate is smaller than a predetermined value, the vehicle is turning with a relatively large turning radius, and the turning performance by the canvas last is demonstrated. It is considered that no improvement is necessary. In such a case, imparting a camber angle to the wheel unnecessarily increases the rolling resistance of the wheel, leading to a reduction in fuel consumption performance.

  Therefore, according to the vehicle control device of the present invention, when the steering angle of the left and right front wheels is larger than a predetermined value or when the yaw rate of the vehicle is larger than a predetermined value, the vehicle is turned with a relatively small turning radius. Therefore, by giving camber angle and exerting canvas last, while ensuring the turning performance, the steering angle of the left and right front wheels is smaller than the predetermined value and the yaw rate of the vehicle is lower than the predetermined value When the vehicle is small, the vehicle is turning with a relatively large turning radius. Therefore, by not providing the camber angle, a wasteful increase in rolling resistance can be suppressed and fuel efficiency can be improved.

  According to the vehicle control device of the third aspect, in addition to the effect produced by the vehicle control device according to the first or second aspect, the vehicle yaw rate is determined based on the yaw rate reference value (that is, the steering of the current left and right front wheels). When the yaw rate determination means determines that the yaw rate is smaller than the value of the yaw rate that should be generated in the vehicle from the corner, after the camber angle adjusting device is activated, the rear outer wheel side of the left and right rear wheels becomes Since it is configured to give a negative camber or a positive camber to the wheel, the rolling resistance can be increased by applying an unnecessary camber angle while securing the turning performance by exerting the canvas last or the action of the force that rotates the vehicle. This has the effect of suppressing the fuel consumption performance.

  That is, since the yaw rate of the vehicle changes in proportion to the steering angle of the left and right front wheels, if the yaw rate of the vehicle matches the reference value of the yaw rate (that is, if it is not smaller than the reference value), the left and right This means that the vehicle is turning properly at the yaw rate corresponding to the steering angle of the front wheels, and that the wheels are gripping the road surface. It is thought that the turning performance is sufficient only by giving the camber angle. In such a case, providing the camber angle to the rear wheel in addition to the front wheel unnecessarily increases the rolling resistance of the wheel, leading to a reduction in fuel consumption performance.

  Therefore, according to the vehicle control device of the present invention, when the yaw rate of the vehicle is smaller than the reference value of the yaw rate, a camber angle is given to the rear wheel (the rear wheel on the turning outer wheel side) in addition to the front wheel. By doing so, the canvas last can be exhibited, and accordingly, the turning performance can be ensured and the vehicle can be appropriately turned at the yaw rate corresponding to the steering angle of the left and right front wheels.

  In addition, by giving a negative camber to the rear wheel on the turning outer wheel side, canvas last can be exhibited and turning performance can be ensured. On the other hand, by giving a positive camber (that is, a camber angle in the opposite phase to the front wheel on the turning outer wheel side) to the rear wheel on the turning outer wheel side, canvas lasts in opposite directions are generated on the front wheel and the rear wheel, Thereby, the force which rotates a vehicle can be exhibited and turning performance can be ensured.

  According to the vehicle control device of the fourth aspect, in addition to the effect produced by the vehicle control device according to the third aspect, the lateral acceleration of the vehicle is determined by the lateral acceleration determination means by the reference value of the lateral acceleration (that is, the current value). If it is determined from the steering angle of the left and right front wheels that it is smaller than the lateral acceleration value that should be generated in the vehicle, a positive camber is applied to the rear wheels on the turning outer wheel side of the left and right rear wheels In addition, if it is determined that the lateral acceleration is larger than the reference value, the negative camber is applied to the rear wheel on the turning outer wheel side of the left and right rear wheels. There is an effect that the turning performance can be effectively secured by the action of the force for rotating the.

  In other words, when the lateral acceleration of the vehicle is smaller than the reference value of the lateral acceleration, it is considered that the vehicle is in an understeer state where the vehicle turns with a turning radius larger than the turning radius corresponding to the steering angle of the left and right front wheels. By applying a positive camber (that is, a camber angle in the opposite phase to the front wheel on the turning outer wheel side) to the rear wheel on the turning outer wheel side, the turning force of the vehicle can be exerted to ensure turning performance. it can.

  That is, in this case, the canvas last of the front wheel on the turning outer wheel side to which the negative camber is applied acts on the vehicle as a force for moving the front side portion of the vehicle toward the turning inward, and is given a positive camber. The rear wheel on the side of the turning outer wheel acts on the vehicle as a force that moves the rear portion of the vehicle toward the outside of the turning, so that the vehicle is easily rotated in the yaw direction, and turning performance is ensured.

  On the other hand, when the lateral acceleration of the vehicle is larger than the reference value of the lateral acceleration, the vehicle is in an oversteer state where the vehicle turns with a turning radius smaller than the turning radius corresponding to the steering angle of the left and right front wheels. It is considered that a large lateral load is acting. In this case, since it is necessary to suppress the wheel from slipping, turning performance can be ensured by applying a negative camber to the rear wheel on the turning outer wheel side to make the wheel difficult to slip.

  According to the vehicle control device of the fifth aspect, when the camber angle actuating device is operated, the camber angles of the left and right front wheels and the left and right rear wheels are independently adjusted, and these left and right front wheels or left and right rear wheels are adjusted. A predetermined camber angle is given to a part or all of.

  Here, according to the vehicle control device of the present invention, the camber angle adjusting device is operated by the front wheel camber control means, and the camber angle is given to exert the canvas last on the wheel, and accordingly, the turning performance. There is an effect that can be secured.

  Here, for example, when the friction coefficient of the road surface is relatively high and a grip force can be expected, or when the vehicle is running straight ahead, it is not necessary to improve the turning performance and to give the camber angle to the wheel, According to the vehicle control device of the present invention, it is estimated that the road surface friction coefficient is lower than a predetermined value, according to the vehicle control device of the present invention. In addition, the camber angle is given only to the front wheels when the traveling state determination means determines that the vehicle is turning, thus ensuring both turning performance and improving fuel efficiency. can do.

  In addition, since the yaw rate of the vehicle changes in proportion to the steering angle of the left and right front wheels, if the yaw rate of the vehicle is larger than a predetermined value (for example, a reference value of the yaw rate) (if it is not smaller than the reference value), Since the vehicle is turning properly at the yaw rate corresponding to the steering angle and the wheels are gripping the road surface, it is relatively unnecessary to improve the turning performance due to the canvas last (ie, camber to the front wheels). It is thought that turning performance is sufficient only by the addition of corners). In such a case, providing the camber angle to the rear wheel in addition to the front wheel unnecessarily increases the rolling resistance of the wheel, leading to a reduction in fuel consumption performance.

  On the other hand, according to the vehicle control device of the present invention, when the yaw rate of the vehicle is smaller than a predetermined value, in addition to the front wheels, rear wheels (for example, only the rear wheels on the turning outer wheel side or the left and right rear wheels). In addition, since the camber angle is given to the canvas last, the turning performance can be ensured and the fuel efficiency can be improved efficiently.

  In this case, when a negative camber is applied to the rear wheel on the turning outer wheel side, the canvas last can be exhibited and the turning performance can be ensured. On the other hand, when a positive camber (that is, a camber angle having a phase opposite to that of the front wheel on the turning outer wheel side) is applied to the rear wheel on the turning outer wheel side, canvas lasts in opposite directions are generated on the front wheel and the rear wheel. As a result, a force for rotating the vehicle can be exerted, and turning performance can be ensured.

  According to the vehicle control device of the sixth aspect, in addition to the effect exerted by the vehicle control device according to any one of the first to fifth aspects, the left and right front wheels and the left and right rear wheels have high gripping characteristics. Since the first tread that is configured and the second tread that is configured to have a low rolling resistance are provided and the ground contact area of the first tread is increased by applying the negative camber, the turning performance is ensured. The fuel efficiency can be improved.

  That is, when it is necessary to ensure turning performance, as described above, by applying a negative camber to the front wheel on the turning outer wheel side, the canvas last can be exerted to ensure turning performance. In addition to this, in this case, since the ground contact area on the first tread side is increased, it is possible to further secure the turning performance by securing the grip force of the wheel.

  On the other hand, when traveling straight ahead or when the steering angle of the left and right front wheels does not reach the predetermined value, the negative camber is not provided, and the contact area of the second tread can be secured accordingly, so that the rolling resistance This can reduce fuel consumption and improve fuel efficiency. Even when it is necessary to ensure turning performance, the negative camber is applied to the front wheel on the turning outer wheel side, and the negative camber is not applied to the front wheel on the turning inner wheel side. Therefore, since the contact area of the second tread can be ensured, the rolling resistance can be reduced and the fuel efficiency can be improved.

  Furthermore, when a positive camber (that is, a camber angle having a phase opposite to that of the front wheel serving as the turning outer wheel) is applied to the rear wheel serving as the turning outer wheel side, the force for rotating the vehicle in the yaw direction is exhibited. As described above, the rear wheel has a role of applying a force (a force in the same direction as the centrifugal force) that moves the rear portion of the vehicle toward the outside of the turn to the vehicle. Not. Therefore, in this case, a positive camber is given to the rear wheel on the side of the turning outer wheel, and the contact area of the second tread is increased, so that the rolling resistance is reduced while ensuring the turning performance, and the fuel efficiency performance is improved. Improvements can be made.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram schematically showing a vehicle 1 on which a vehicle control device 100 according to the first embodiment of the present invention is mounted. Note that arrows UD, LR, and FB in FIG. 1 indicate the up-down direction, the left-right direction, and the front-rear direction of the vehicle 1, respectively.

  First, a schematic configuration of the vehicle 1 will be described. As shown in FIG. 1, the vehicle 1 includes a vehicle body frame BF, a plurality of (four wheels in the present embodiment) wheels 2 that support the vehicle body frame BF, and some of the wheels 2 (this embodiment). In this embodiment, the wheel drive device 3 that rotationally drives the left and right front wheels 2FL, 2FR, the suspension device 4 that connects the wheel 2 and the vehicle body frame BF, and a part of each wheel 2 (in this embodiment) And the steering device 5 for steering the left and right front wheels 2FL, 2FR), and by controlling the camber angle of the wheel 2, the turning performance (running performance) can be ensured and the fuel efficiency (fuel efficiency) can be improved. It is comprised so that it can aim at.

  Next, the detailed configuration of each part will be described. As shown in FIG. 1, the wheel 2 includes left and right front wheels 2FL and 2FR located on the front side (arrow F direction side) of the vehicle 1 and left and right rear wheels located on the rear side (arrow B direction side) of the vehicle 1. Wheels 2RL and 2RR are provided. In the present embodiment, the left and right front wheels 2FL, 2FR are configured as driving wheels that are rotationally driven by the rotational driving force applied from the wheel driving device 3, while the left and right rear wheels 2RL, 2RR are configured as vehicles. It is comprised as a driven wheel driven by 1 driving | running | working.

  As described above, the wheel drive device 3 is a device for rotationally driving the left and right front wheels 2FL and 2FR, and is configured by an electric motor 3a as described later (see FIG. 3). Further, as shown in FIG. 1, the electric motor 3 a is connected to the left and right front wheels 2 FL and 2 FR via a differential gear (not shown) and a pair of drive shafts 31.

  When the driver operates the accelerator pedal 61, a rotational driving force is applied from the wheel drive device 3 to the left and right front wheels 2FL, 2FR, and the left and right front wheels 2FL, 2FR rotate according to the operation amount of the accelerator pedal 61. Driven at speed. The difference in rotation between the left and right front wheels 2FL and 2FR is absorbed by the differential gear.

  The suspension device 4 functions as a so-called suspension for mitigating vibration transmitted from the road surface to the vehicle body frame BF via the wheels 2, and is provided corresponding to each wheel 2 as shown in FIG. It has been. Further, the suspension device 4 in the present embodiment also has a function as a camber angle adjusting mechanism for adjusting the camber angle of the wheel 2.

  Here, with reference to FIG. 2, the detailed structure of the suspension apparatus 4 is demonstrated. FIG. 2 is a front view of the suspension device 4. Since the configuration of each suspension device 4 is common to each wheel 2, the suspension device 4 corresponding to the right front wheel 2FR is shown in FIG. 2 as a representative example. However, in FIG. 2, illustration of the drive shaft 31 and the like is omitted for easy understanding.

  As shown in FIG. 2, the suspension device 4 mainly includes a shock absorber 41, a lower arm 42, an axle carrier 43, and an FR actuator 44FR, and is configured as a strut suspension.

  The shock absorber 41 attenuates vibration transmitted to the vehicle body frame BF by expanding and contracting, and is configured by a so-called damper. As shown in FIG. 2, the upper end (upper side in FIG. 2) is connected to the vehicle body frame BF. The lower end (lower side in FIG. 2) is connected to the vehicle body frame BF via the lower arm 42.

  Further, the shock absorber 41 includes a connecting arm 41a as shown in FIG. The connecting arm 41a connects the axle carrier 43 to the shock absorber 41. One end (right side in FIG. 2) is fixed to the lower end side of the shock absorber 41, and the other end (left side in FIG. 2) connects the camber shaft 45. Via the axle carrier 43.

  As described above, the lower arm 42 connects the lower end of the shock absorber 41 to the vehicle body frame BF. As shown in FIG. 2, one end (right side in FIG. 2) is connected to the vehicle body frame BF, and the other end (left side in FIG. 2). ) Are pivotally supported on the shock absorber 41 via rubber bushes (not shown).

  The axle carrier 43 rotatably supports the wheel 2 and is connected to the shock absorber 41 via a connecting arm 41a and an FR actuator 44FR as shown in FIG.

  The FR actuator 44FR is a device for connecting the axle carrier 43 to the shock absorber 41 and adjusting the distance between the axle carrier 43 and the shock absorber 41, and is constituted by a hydraulic cylinder. As shown in FIG. 2, the FR actuator 44FR has a main body portion (right side in FIG. 2) pivotally supported by the shock absorber 41 and a rod portion (left side in FIG. 2) connected to the axle carrier 43 via a ball joint. ing.

  According to the suspension device 4 configured as described above, when the FR actuator 44FR is driven to extend and contract, the wheel 2 is driven to swing around the camber shaft 45, and a predetermined camber angle is imparted to the wheel 2. .

  Further, for example, when a person gets on the vehicle 1 or loads are loaded and the suspension device 4 (shock absorber 41) strokes, the wheel 2 swings around the camber shaft 45 as a central axis, and the wheel 2 with respect to the vehicle body frame BF. Camber angle (hereinafter referred to as “versus-vehicle camber angle”) changes.

  Returning to FIG. The steering device 5 is a device for transmitting the operation of the steering 63 by the driver to the left and right front wheels 2FL, 2FR to perform a steering operation, and is configured as a so-called rack and pinion type steering gear.

  According to the steering device 5, the operation (rotation) of the steering 63 by the driver is first transmitted to the universal joint 52 via the steering column 51, and the pinion 53 a of the steering box 53 is changed while the angle is changed by the universal joint 52. Is transmitted as rotational motion. Then, the rotational motion transmitted to the pinion 53a is converted into a linear motion of the rack 53b, and the tie rod 54 connected to both ends of the rack 53b moves by the linear motion of the rack 53b. As a result, the tie rod 54 pushes and pulls the knuckle 55, so that a predetermined steering angle is given to the wheel 2.

  The accelerator pedal 61 and the brake pedal 62 are operated by the driver, and the traveling speed and braking force of the vehicle 1 are determined in accordance with the operation state of each pedal 61, 62 (stepping amount, stepping speed, etc.). Then, drive control of the wheel drive device 3 is performed. The steering 63 is operated by the driver, and the steering operation of the wheel 2 by the steering device 5 is performed according to the operation state (rotation angle, rotation speed, etc.).

  The wiper switch 64 is an operation member that is arbitrarily operated by the driver, and according to the operation state (operation position, etc.), wipers (such as raindrops adhering to the surface of the windshield and rear glass) are thinned and evenly distributed. A device for ensuring visibility (not shown) is controlled. The camber switch 65 is an operation member that is arbitrarily operated by the driver, and the operation control of the camber angle adjusting device 4 is performed according to the operation state (operation position, etc.).

  The state in which the camber switch 65 is turned on corresponds to the state in which the application of the negative camber to the wheel 2 is selected, and a negative camber of a predetermined angle is applied to the wheel 2 (front wheels 2FL, 2RR and rear wheels 2RL, 2RR). Is granted. However, even when the camber switch 65 is turned on, if a predetermined condition is satisfied, the camber angle of each wheel 2 is changed to another camber angle (including 0 degrees) as described later. (See FIG. 5).

  The navigation device 82 is a device for acquiring the current position of the vehicle 1 and acquiring information on the current position of the vehicle 1 using GPS. The information at the current position is configured such that the road surface on which the vehicle 1 travels can be obtained such as the state of inclination (inclination angle and direction), the friction coefficient of the road surface, the road width, and the curve radius.

  The vehicle control device 100 is a device for controlling each part of the vehicle 1 configured as described above. For example, the operation state of the pedals 61 and 62 is detected, and a wheel drive device is detected according to the detection result. The wheel 3 is rotationally driven by drivingly controlling the wheel 3. Moreover, the camber angle of each wheel 2 is suppressed by drivingly controlling the camber angle adjusting device 44 (see FIG. 3) according to the operation state of each configuration described above.

  Next, a detailed configuration of the vehicle control device 100 will be described with reference to FIG. FIG. 3 is a block diagram showing an electrical configuration of the vehicle control device 100. As shown in FIG. 3, the vehicle control device 100 includes a CPU 71, a ROM 72, and a RAM 73, which are connected to an input / output port 75 via a bus line 74. The input / output port 75 is connected to devices such as the wheel drive device 3.

  The CPU 71 is an arithmetic unit that controls each unit connected by the bus line 74. The ROM 72 is a non-rewritable nonvolatile memory storing a control program executed by the CPU 71, fixed value data, and the like, and the RAM 73 is a memory for storing various data in a rewritable manner when the control program is executed. . The ROM 72 stores a program of the flowcharts (camber control processing and camber provision processing) illustrated in FIGS. 4 and 5.

  Further, the ROM 72 is provided with a yaw rate map 72a and a lateral acceleration map 72b as shown in FIG. The yaw rate map 72a includes the steering angle of the left and right front wheels 2FL and 2FR and the yaw rate (the reference value of the yaw rate) that should be generated in the vehicle 1 when the vehicle 1 travels without slipping the wheel 2 at the steering angle. , Stored in association with the vehicle speed of the vehicle 1. The CPU 71 acquires the steering angle of the left and right front wheels 2FL, 2FR and the vehicle speed of the vehicle 1, and reads the yaw rate corresponding to the steering angle and the vehicle speed from the yaw rate map 72a.

  The lateral acceleration map 72b shows the steering angle of the left and right front wheels 2FL, 2FR and the lateral acceleration (reference value of the lateral acceleration) to be generated in the vehicle 1 when the vehicle 1 travels without slipping the wheel 2 at the steering angle. ) Is stored in association with the vehicle speed of the vehicle 1. The CPU 71 acquires the steering angles of the left and right front wheels 2FL, 2FR and the vehicle speed of the vehicle 1, and reads the lateral acceleration corresponding to the steering angle and the vehicle speed from the lateral acceleration map 72b.

  As described above, the wheel drive device 3 is a device for rotationally driving the left and right front wheels 2FL, 2FR (see FIG. 1), and an electric motor 3a that applies a rotational driving force to the left and right front wheels 2FL, 2FR. A drive control circuit (not shown) for driving and controlling the electric motor 3a based on a command from the CPU 71 is mainly provided. However, the wheel drive device 3 is not limited to the electric motor 3a, and other drive sources can naturally be adopted. Examples of other drive sources include a hydraulic motor and an engine.

  The acceleration sensor device 32 is a device for detecting the acceleration of the vehicle 1 and outputting the detection result to the CPU 71. The acceleration sensor device 32a includes a longitudinal acceleration sensor 32a, a lateral acceleration sensor 32b, and acceleration sensors 32a and 32b. It mainly includes a control circuit (not shown) that processes the detection result and outputs it to the CPU 71.

  The longitudinal acceleration sensor 32a is a sensor that detects acceleration in the longitudinal direction (the direction of arrow FB in FIG. 1) of the vehicle 1 (body frame BF), and the lateral acceleration sensor 32b is the vehicle 1 (body frame BF). This is a sensor that detects acceleration in the left-right direction (arrow LR direction in FIG. 1). In the present embodiment, each of the acceleration sensors 32a and 32b is configured as a piezoelectric sensor using a piezoelectric element.

  Further, the CPU 71 calculates the ground speed (absolute value and traveling direction) of the vehicle 1 with respect to the road surface from the detection result of the acceleration sensor device 32. That is, the CPU 71 time-integrates the detection results (acceleration values) of the respective acceleration sensors 32a and 32b input from the control circuit of the vehicle speed sensor device 32, and calculates speeds in two directions (front and rear and left and right directions), respectively. At the same time, the ground speed (absolute value and traveling direction) of the vehicle 1 is obtained by synthesizing these two direction components.

  The camber angle adjusting device 44 is a device for adjusting the camber angle of each wheel 2, and, as described above, a total of four FL to RR actuators 44FL to 44RR that give camber angles to each wheel 2, respectively, The actuator 44FL to 44RR is mainly provided with a drive control circuit (not shown) for controlling driving of the actuators 44FL to 44RR based on a command from the CPU 71.

  As described above, the FL to RR actuators 44FL to 44RR are constituted by hydraulic cylinders, and a hydraulic pump (not shown) that supplies oil (hydraulic pressure) to each hydraulic cylinder, and from the hydraulic pump to each hydraulic cylinder. An electromagnetic valve (not shown) for switching the supply direction of supplied oil is mainly provided.

  When the drive control circuit of the camber angle adjusting device 44 drives and controls the hydraulic pump based on an instruction from the CPU 71, each hydraulic cylinder (FL to RR actuators 44FL to 44RR) is expanded and contracted by the oil supplied from the hydraulic pump. The When the solenoid valve is turned on / off, the driving direction (extension or contraction) of each hydraulic cylinder (FL to RR actuators 44FL to 44RR) is switched.

  The CPU 71 detects the camber angle of each wheel 2 with respect to the vehicle camber angle sensor device 80 described later, and instructs the drive control circuit of the camber angle adjustment device 44 until the camber angle with respect to the vehicle body of each wheel 2 reaches the target value. Send. In the present embodiment, the camber angle of each wheel 2 is set to a steady angle of 0 degrees, and if it is determined that a predetermined condition is satisfied, a negative camber or a positive camber is applied to some wheels 2. (See S13, S18, and S19 in FIG. 5) and when it is determined that the predetermined condition is not satisfied, the camber angles of some of the wheels 2 are returned to the steady angle (0 degree). The

  The camber angle sensor device 80 is a device for detecting the camber angle of each wheel 2 (camber angle with respect to the vehicle body) and outputting the detection result to the CPU 71. The camber angle of each wheel 2 is generated in the direction of generation (positive direction). Or a total of four FL to RR camber angle sensors 80FL to 80RR detected in association with the negative direction), and a processing circuit (not shown) that processes the detection results of the camber angle sensors 80FL to 80RR and outputs them to the CPU 71. )).

  In the present embodiment, each of the camber angle sensors 80FL to 80RR is configured as a millimeter wave radar that measures the angle of the object using millimeter waves. Each of these camber angle sensors 80FL to 80RR is disposed on the body frame BF (see FIG. 1) and transmits a millimeter wave toward each wheel 2 to measure the angle of the axle carrier 43, thereby A camber angle with respect to the vehicle body can be obtained. However, each of the camber angle sensors 80FL to 80RR is not limited to the millimeter wave radar, and other types of radars can naturally be employed. Examples of other types of radar include an infrared radar and an ultrasonic radar.

  The yaw rate sensor device 81 is a device for detecting the yaw rate of the vehicle 1 and outputting the detection result to the CPU 71. The yaw rate sensor detects the rotational angular velocity around the vertical axis of the body frame BF in association with the rotational direction. 81a and a processing circuit (not shown) for processing the detection result and outputting the result to the CPU 71. The yaw rate is a rotation in a plane (plane including the arrows FD and LR in FIG. 1) that is horizontal to the road surface with the vertical axis (the axis in the direction of arrow UD in FIG. 1) as the center. ) Angular velocity.

  In the present embodiment, the yaw rate sensor 81a is constituted by an optical gyro sensor that detects the rotational angular velocity by the Sagnac effect. However, it is naturally possible to employ other types of gyro sensors. Examples of other types of gyro sensors include mechanical and fluid gyro sensors.

  As described above, the navigation device 82 is a device for acquiring the current position of the vehicle 1 using GPS and acquiring information at the current position of the vehicle 1. A current position acquisition unit (not shown) for acquiring one current position, an information storage unit (not shown) for storing various types of information in association with map data, etc., and a vehicle acquired by the current position acquisition unit 1 mainly includes a processing circuit (not shown) that processes various information stored in the current position and information storage unit 1 and outputs the processed information to the CPU 71. The CPU 71 can obtain various information at the current position of the vehicle 1 based on the current position of the vehicle 1 and various information input from the navigation device 82.

  The navigation device 82 according to the present embodiment includes an information storage unit that stores various types of information in association with map data or the like, but instead of the information storage unit, various types of information are associated with map data or the like. An information reading unit that reads road surface information from a stored storage medium may be provided, and various information read by the information reading unit may be output to the CPU 71.

  The ground load sensor device 34 is a device for detecting the load received by the ground contact surface of each wheel 2 from the road surface and outputting the detection result to the CPU 71. FL to RR for detecting the load received by each wheel 2 respectively. Load sensors 34FL to 34RR and a processing circuit (not shown) for processing the detection results of the load sensors 34FL to 34RR and outputting the results to the CPU 71 are provided.

  In the present embodiment, each of the load sensors 34FL to 34RR is configured as a piezoresistive triaxial load sensor. Each of these load sensors 34FL to 34RR is disposed on the suspension shaft of each wheel 2 and receives the load received by the wheel 2 from the road surface in the front-rear direction (the arrow FD direction in FIG. 1) and the left-right direction (see FIG. Detection is performed in three directions (1 arrow LR direction) and up and down direction (arrow UD direction in FIG. 1) (see FIG. 1).

  The CPU 71 estimates the friction coefficient μ of the road surface on the ground contact surface of each wheel 2 from the detection results (ground load) of the load sensors 34FL to 34RR input from the ground load sensor device 34 as follows. For example, paying attention to the front wheel 2FL, if the loads in the front-rear direction, the left-right direction, and the up-down direction of the vehicle 1 detected by the FL load sensor 34FL are Fx, Fy, and Fz, respectively, the portion corresponding to the ground contact surface of the front wheel 2FL is detected. The friction coefficient μ in the front-rear direction of the vehicle 1 on the road surface is Fx / Fz (μx = Fx / Fz) in a slip state where the front wheel 2FL is slipping with respect to the road surface, and the front wheel 2FL is not slipping with respect to the road surface. In the slip state, it is estimated that the value is larger than Fx / Fz (μx> Fx / Fz).

  The same applies to the friction coefficient μy in the left-right direction of the vehicle 1. In the slip state, μy = Fy / Fz, and in the non-slip state, the value is estimated to be larger than Fy / Fz. Of course, it is possible to detect the friction coefficient μ by other methods. Examples of other techniques include known techniques disclosed in Japanese Patent Application Laid-Open Nos. 2001-315633 and 2003-118554.

  The wheel rotation speed sensor device 35 is a device for detecting the rotation speed of each wheel 2 and outputting the detection result to the CPU 71. Four FL to RR rotations for detecting the rotation speed of each wheel 2 respectively. Speed sensors 35FL to 35RR and a processing circuit (not shown) that processes the detection results of the rotational speed sensors 35FL to 35RR and outputs them to the CPU 71 are provided.

  In this embodiment, each rotation sensor 35FL-35RR is provided in each wheel 2, and detects the angular velocity of each wheel 2 as a rotation speed. That is, each rotation sensor 35FL-35RR is an electromagnetic pickup provided with a rotating body that rotates in conjunction with each wheel 2 and a pickup that electromagnetically detects the presence or absence of a large number of teeth formed in the circumferential direction of the rotating body. It is configured as a sensor of the type.

  The CPU 71 calculates the rotation speed of each wheel 2 based on the detection results of the rotation sensors 35FL to 35RR input from the wheel rotation speed sensor device 35, and calculates the ground speed based on the calculated average value of the rotation speed of each wheel 2. The speed (vehicle speed of the vehicle 1) can be obtained.

  Further, the CPU 71 obtains the actual peripheral speed of each wheel 2 from the rotational speed of each wheel 2 input from the wheel rotational speed sensor device 35 and the outer diameter of each wheel 2 stored in advance in the ROM 72. It is possible to determine whether or not each wheel 2 is slipping by comparing the peripheral speed with the traveling speed (ground speed) of the vehicle 1.

  The accelerator pedal sensor device 61a is a device for detecting the operation state of the accelerator pedal 61 and outputting the detection result to the CPU 71. An angle sensor (not shown) for detecting the depression amount of the accelerator pedal 61; A processing circuit (not shown) that processes the detection result of the angle sensor and outputs the result to the CPU 71 is provided.

  The brake pedal sensor device 62a is a device for detecting the operation state of the brake pedal 62 and outputting the detection result to the CPU 71. An angle sensor (not shown) for detecting the depression amount of the brake pedal 62; A processing circuit (not shown) that processes the detection result of the angle sensor and outputs the result to the CPU 71 is provided.

  The steering sensor device 63a is a device for detecting the operation state of the steering 63 and outputting the detection result to the CPU 71, and an angle sensor (not shown) for detecting the operation amount (rotation angle) of the steering 63. And a processing circuit (not shown) that processes the detection result of the angle sensor and outputs the result to the CPU 71.

  In the present embodiment, each angle sensor is configured as a contact-type potentiometer using electric resistance. The CPU 71 obtains the depression amounts of the pedals 61 and 62 and the rotation angle of the steering 63 from the detection results of the angle sensors input from the sensor devices 61a, 62a and 63a, and time-differentiates the detection results. The depression speed of each pedal 61, 62 and the rotation speed of the steering 63 can be obtained.

  In the present embodiment, as described above, since the steering device 5 is configured as a rack and pinion type steering gear, the operating angle of the steering 63 by the driver and the steering angles of the left and right front wheels 2FL and 2FR Is in a proportional relationship. Therefore, the “steering angle of the left and right front wheels” described in the claims of the present invention can be determined from the detection result of the steering sensor device 63a.

  The wiper switch sensor device 64a is a device for detecting the operation state of the wiper switch 64 and outputting the detection result to the CPU 71, and a positioning sensor (not shown) for detecting the operation state (operation position) of the wiper switch 64. And a control circuit (not shown) for processing the detection result of the positioning sensor and outputting the result to the CPU 71.

  The camber switch sensor device 65a is a device for detecting the operation state of the camber switch 65 and outputting the detection result to the CPU 71, and a positioning sensor (not shown) for detecting the operation state (operation position) of the camber switch 56. And a control circuit (not shown) for processing the detection result of the positioning sensor and outputting the result to the CPU 71.

  The weather information radio device 66a obtains weather information using a so-called FM text multiplex broadcasting service (which transmits digital signals using FM radio gaps and transmits a plurality of independent text information simultaneously with radio broadcasting). A receiving unit (not shown) for receiving a digital signal, an acquiring unit for processing the digital signal received by the receiving unit to acquire weather information, and the weather acquired by the acquiring unit An output unit (not shown) for outputting information to the CPU 71 is mainly provided. The CPU 71 can obtain weather information at the current position of the vehicle 1 based on the weather information input from the weather information radio device 66a and the position information input from the navigation device 82 described above.

  The outside air temperature sensor device 67a is a device for detecting the temperature outside the vehicle (outside air temperature) of the vehicle 1 and outputting the detection result to the CPU 71, and a temperature sensor (not shown) for detecting the outside air temperature; It mainly includes a control circuit (not shown) that processes the detection result of the temperature sensor and outputs it to the CPU 71.

  As another input / output device 36 shown in FIG. 3, this embodiment includes a VICS device. The VICS device is a device for acquiring traffic information using a VICS system (a system that transmits various types of information edited and processed at the VICS center in real time from FM multiplex broadcasting or a transmitter on the road). Receiving unit (not shown) for receiving the received signal, an acquiring unit for processing the signal received by the receiving unit to acquire traffic information, and an output for outputting the traffic information acquired by the acquiring unit to CPU 71 Part (not shown). Based on the traffic information input from the VICS device, the CPU 71 can obtain the road surface condition (for example, whether or not it is a winter regulation) at the current position of the vehicle 1.

  Other examples of the input / output device 36 shown in FIG. 3 include, for example, a rain sensor for detecting the rainfall and an optical sensor for detecting the road surface state in a non-contact manner.

  Next, camber braking control will be described with reference to FIG. FIG. 4 is a flowchart showing camber control processing. This process is a process that is repeatedly executed by the CPU 71 (for example, at intervals of 0.2 ms) while the power of the vehicle control device 100 is turned on, and suppresses an unnecessary camber angle being imparted. Thus, when it is estimated that the friction coefficient of the road surface is low while improving the fuel consumption performance, the turning performance is ensured by giving a camber angle to the wheel 2.

  With respect to the camber control process, the CPU 71 first determines whether the wiper switch 64 (see FIG. 1) is turned on, that is, whether the wiping operation by the wiper device such as the windshield is instructed by the driver (S1). As a result, when it is determined that the wiper switch 64 is turned on (S1: Yes), it is estimated that the current weather is a weather accompanied by rain or snow, and a water film is formed on the road surface. There may be snow.

  In this case (S1: Yes), since the road surface friction coefficient decreases due to water film or snow accumulation, and the turning performance of the vehicle may be lowered, the camber imparting process (S8) is executed to perform this camber control. The process ends. In the camber imparting process (S8), the necessity of securing the turning performance is determined, and if necessary, the camber angle is given to the wheel 2 to ensure the turning performance by exhibiting the canvas last, while the turning performance. For example, as described above, even if it is raining or snowing, it is prohibited to give a camber angle to the wheel 2, and the rolling resistance of the wheel 2 is unnecessarily increased. To improve fuel efficiency. The camber providing process (S8) will be described later with reference to FIG. 5 after describing the processes up to S7.

  If it is not determined in step S1 that the wiper switch 64 is turned on (S1: No), the current weather is not accompanied by rain or snow, and the road surface is in a state where there is no water film or snow. Then, the process proceeds to S2, and it is determined whether the outside air temperature is equal to or lower than a predetermined value (S2). In the present embodiment, the temperature (predetermined value) that serves as a determination reference in the process of S2 is set to zero degrees Celsius.

  In the process of S2, when it is determined that the outside air temperature is equal to or lower than the predetermined value (S2: Yes), it is estimated that the road surface is frozen and the friction coefficient may be low. Moreover, even if the road surface is not frozen, it is estimated that the tread of the wheel 2 may lose flexibility and reduce the grip force. Therefore, in this case (S2: Yes), the turning performance of the vehicle may be deteriorated, so the camber giving process (S8) is executed and the camber control process is ended.

  On the other hand, in the process of S2, when it is not determined that the outside air temperature is equal to or lower than the predetermined value (S2: No), the possibility that the road surface is frozen is low, and the tread of the wheel 2 maintains flexibility. Since it is presumed that the grip force is secured, the process proceeds to S3 to determine whether the weather information is snow or rain (S3).

  In the process of S3, when it is determined that the weather information is snow or rain (S3: Yes), even if the wiper switch 64 (see FIG. 1) is not turned on, the current weather is determined to be rain or snow. It is possible to estimate that there is a possibility that the weather is accompanied and a water film is formed on the road surface or snow is piled up. Or, even if the current weather is not accompanied by rainfall or snowfall, there is a high possibility that it will change to such weather after that, or it has already stopped raining or snowing, but there is a water film or snowfall on the road surface. There is also a possibility that it remains.

  Therefore, in this case (S3: Yes), the friction coefficient of the road surface is lowered due to water film and snow accumulation, and the turning performance of the vehicle may be lowered. The camber control process is terminated.

  On the other hand, if it is not determined in the process of S3 that the weather information is snow or rain (S3: No), it is estimated that the occurrence of an influence due to rain or snow is low. The navigation information acquired by the navigation device 82 (see FIG. 3) indicates winter and north, that is, the current season is winter, and the current position of the vehicle 1 is the reference position (reference latitude). It is determined whether it is more north (S4). In the present embodiment, the reference latitude serving as a determination reference in the process of S4 is 35 degrees north latitude.

  In the process of S4, when it is determined that the navigation information indicates winter and north (S4: Yes), the current season is winter, and the current position of the vehicle 1 is the reference position (reference latitude). Since it is located more north, in each step described above, for example, even if it is determined that there is currently no rain or snow (S1 to S3: No), for example, the current position is a snowy area, There is a possibility that snow is left on the road surface, or a compressed snow ice burn is formed on the road surface.

  Therefore, in this case (S4: Yes), the coefficient of friction of the road surface may be lowered due to snow accumulation, compressed snow ice burn, etc., and the turning performance of the vehicle may be reduced. Therefore, the camber imparting process (S8) is executed. This camber control process is terminated.

  On the other hand, in the process of S4, when it is not determined that the navigation information indicates winter and north (S4: No), it is estimated that there is a low possibility of snow remaining on the road surface. Then, the process proceeds to the process of S5, and it is determined whether the road information transmits a winter regulation, that is, whether a traffic regulation due to heavy rain or snowfall is transmitted (S5).

  In the process of S5, when it is determined that the road information is transmitting winter regulations (S5: Yes), traffic regulations caused by heavy rain or snow are being transmitted. For example, even if it is currently determined that there is no rainfall or snowfall (S1 to S4: No), there is still snow on the planned road surface (or the road surface during travel) or the slope collapses There is a possibility that the earth and sand from have leaked to the road surface.

  Therefore, in this case (S5: Yes), the coefficient of friction of the road surface may be lowered due to snow accumulation or spilled earth and sand, which may reduce the turning performance of the vehicle. Therefore, the camber imparting process (S8) is executed. This camber control process is terminated.

  On the other hand, in the process of S5, when it is not determined that the road information transmits the winter regulations (S5: No), there is snow on the road surface, or earth and sand are flowing out on the road surface, etc. Since it is estimated that the possibility is low, the process proceeds to step S6, where the camber switch 65 (see FIG. 1) is turned on, that is, the camber angle (negative camber) to the wheel 2 is set by the driver. It is determined whether or not the assignment is instructed (S6).

  In the process of S6, when it is determined that the camber switch 65 is turned on (S6: Yes), the driver has voluntarily instructed to give the camber angle (negative camber) to the wheel 2, that is, There may be some reason that the driver determines that it is necessary to ensure the turning performance by giving the camber angle (for example, oil has been found on the road surface).

  Therefore, in this case (S6: Yes), the coefficient of friction of the road surface is lowered for some reason, and the turning performance of the vehicle may be lowered. Therefore, the camber giving process (S8) is executed, and this camber control process is performed. Exit.

  On the other hand, in the process of S6, when it is not determined that the camber switch 65 is turned on (S6: No), the driver is not instructed to give the camber angle (negative camber) to the wheel 2, Since it is estimated that there is a low possibility that it is necessary to ensure that the turning performance is ensured, the process proceeds to S7, and it is determined whether the friction coefficient of the road surface is equal to or less than a predetermined value. (S7).

  In the process of S7, when it is determined that the friction coefficient of the road surface is equal to or less than a predetermined value (S7: Yes), the vehicle currently has a road surface with a low friction coefficient, which may reduce the turning performance of the vehicle. Since the vehicle is traveling, the camber giving process (S8) is executed, and the camber control process is terminated.

  On the other hand, if it is not determined in the process of S7 that the friction coefficient of the road surface is less than or equal to a predetermined value (S7: No), the vehicle currently has a relatively high friction coefficient, which may reduce the turning performance of the vehicle. Therefore, the camber grant process (S8) is skipped and the camber control process is terminated.

  As described above, in the present embodiment, it is necessary to ensure the turning performance by actually detecting the friction coefficient of the road surface (estimated by the ground load sensor device 34, see FIG. 3) in the process of S7. In addition to this, in the processes of S1 to S6, it is also possible to determine whether it is necessary to ensure turning performance by estimating whether the friction coefficient of the road surface is low using various means. Do.

  Thereby, for example, even when the ground load sensor device 34 fails and the friction coefficient of the road surface cannot be actually detected, it is possible to estimate whether the friction coefficient of the road surface is low by means of S1 to S2. Therefore, the fail safe function can be ensured.

  Next, the camber grant process (S8) will be described with reference to FIG. FIG. 8 is a flowchart showing camber provision processing. This process is a process executed in the above-described camber control process when the road surface friction coefficient is low and it is necessary to ensure turning performance (S1 to S7: Yes), and the camber angle is given to the wheel 2. And the turning performance is ensured by demonstrating the canvas last.

  Regarding the camber giving process (S8), the CPU 71 first determines whether the operation angle of the steering 63 is equal to or greater than a predetermined value, that is, the vehicle 1 is turning and the vehicle 1 is turned with a relatively small turning radius. Is determined (S10). In the present embodiment, the operation angle (predetermined value) that serves as a determination reference in the processing of S10 is an angle that is operated by 50% of the maximum operation angle in the forward and reverse directions around the neutral position of the steering wheel 63. ing.

  In the process of S10, when it is not determined that the operation angle of the steering wheel 63 is equal to or greater than the predetermined value (S10: No), the vehicle 1 is traveling straight or turning with a relatively large turning radius. Since it is considered unnecessary to ensure the turning performance, it is then determined whether the yaw rate of the vehicle 1 is equal to or greater than a predetermined value (S11).

  In the process of S11, when it is not determined that the yaw rate of the vehicle 1 is equal to or greater than the predetermined value (S11: No), the vehicle 1 is moving straight ahead or a relatively large turn as described above. Since it is turning with a radius and it is considered that it is not necessary to ensure turning performance, this camber imparting process (S8) is terminated.

  As described above, when it is determined that the vehicle 1 is turning with a relatively large turning radius and it is not necessary to improve the turning performance by exhibiting the canvas last (S10 and S11: No), the camber applying process ( By terminating S8) and avoiding the camber angle being given to the wheel 2 unnecessarily, the rolling resistance of the wheel 2 can be prevented from increasing unnecessarily, and the fuel efficiency can be improved. it can.

  On the other hand, in the process of S10, when it is determined that the operation angle of the steering wheel 63 is greater than or equal to a predetermined value (S10: Yes), and in the process of S11, the yaw rate of the vehicle 1 is determined to be greater than or equal to the predetermined value. In this case (S11: Yes), the vehicle 1 is turning with a relatively small turning radius, and it is considered necessary to ensure turning performance. Therefore, first, the turning direction is acquired (S12), and then turning. A negative camber is applied to the front wheels 2FL and 2FR on the outer ring side (S13).

  As a result, a negative camber is applied to the front wheels 2FL and 2FR on the turning outer wheel side, so that the front wheels 2FL and 2FR on the turning outer wheel side exhibit canvas last, and accordingly, the turning performance can be secured. it can.

  In particular, in the present embodiment, the wheel 2 to which the negative camber is applied is the front wheels 2FL and 2FR on the turning outer wheel side, and this is the wheel 2 in which the ground contact load increases during turning. Therefore, since the influence of canvas last can be increased, it is possible to efficiently ensure the turning performance accordingly.

  That is, if a negative camber is applied to all the wheels 2, the increase in the rolling resistance of the wheels 2 due to the canvas last causes a reduction in fuel consumption performance. As described above, the wheels 2 that can efficiently generate the canvas last. (In other words, the negative camber is applied only to the front wheels 2FL and 2FR on the turning outer wheel side, so that the increase in rolling resistance is suppressed to the minimum while ensuring the turning performance. Can be improved.

  After the process of S13 is executed and the negative camber is applied to the front wheels 2FL and 2FR on the turning outer wheel side (S13), the negative camber is applied to the front wheels 2FL and 2FR on the turning outer wheel side by the process of S13. The yaw rate of the vehicle 1 in the state is acquired (S14), and it is determined whether the acquired yaw rate is equal to or greater than a predetermined value, that is, equal to or greater than the reference value of the yaw rate (S15).

  The reference value of the yaw rate is a value stored in the yaw rate map 72a (see FIG. 3) as described above, and the CPU 71 operates the steering angle of the left and right front wheels 2FL, 2FR (that is, the operation of the steering 63). Angle) and a value corresponding to the vehicle speed of the vehicle 1 (a reference value of the yaw rate) is read from the yaw rate map 72a, and based on the read value, a determination is made in the processing of S15.

  In the process of S15, when it is determined that the yaw rate acquired in the process of S14 is equal to or greater than a predetermined value (S15: Yes), the vehicle 1 is appropriate at the yaw rate corresponding to the steering angle of the left and right front wheels 2FL, 2FR. Therefore, it is not necessary to improve the turning performance by demonstrating the canvas last (that is, the camber angle to the front wheels 2FL and 2FR on the turning outer wheel side). It is thought that turning performance is sufficient only by the provision of the In such a case, in addition to the front wheels 2FL and 2FR, as will be described later, adding a camber angle to the rear wheels 2RL and 2RR (see S16 to S19) unnecessarily increases the rolling resistance of the wheel 2. As a result, the fuel efficiency is lowered.

  Therefore, in the present embodiment, in the process of S15, when it is not determined that the yaw rate acquired in the process of S13 is equal to or greater than a predetermined value (equivalent or larger than the reference value of the yaw rate) (S15: Yes), S16 The process of S19 is skipped and this camber provision process (S8) is complete | finished. As a result, it is possible to prevent the camber angle from being given to the wheel 2 unnecessarily, and to prevent the rolling resistance of the wheel 2 from increasing unnecessarily, so that the fuel efficiency is improved accordingly. Can do.

  On the other hand, in the process of S15, when it is not determined that the yaw rate acquired in the process of S13 is greater than or equal to the predetermined value, that is, it is determined that the yaw rate is smaller than the reference value of the yaw rate (S15: No), the left and right front wheels Since the vehicle 1 is not properly turning at the yaw rate corresponding to the steering angle of 2FL and 2FR, and the turning performance is considered insufficient, the camber angle is also given to the rear wheels 2RL and 2RR to turn In order to ensure performance, the processes of S16 to S19 are executed.

  That is, when giving the camber angle to the rear wheels 2RL and 2RR, the CPU 71 first acquires the lateral acceleration of the vehicle 1 in the process of S16 (S16), and whether the acquired lateral acceleration is equal to or greater than a predetermined value. That is, it is determined whether it is equal to or larger than the reference value of the lateral acceleration (S17).

  The reference value of the lateral acceleration is a value stored in the lateral acceleration map 72b (see FIG. 3) as described above, and the CPU 71 determines the steering angle (that is, the steering 63) of the left and right front wheels 2FL, 2FR. ) And the vehicle speed of the vehicle 1 (reference value of the lateral acceleration) is read from the lateral acceleration map 72b, and based on the read value, a determination is made in the processing of S17.

  In the process of S17, when it is not determined that the lateral acceleration acquired in the process of S16 is greater than or equal to a predetermined value, that is, when it is determined that the lateral acceleration is smaller than the reference value of the lateral acceleration (S17: No), the left and right front wheels Since the vehicle 1 is considered to be understeered with a turning radius larger than the turning radius corresponding to the steering angle of 2FL, 2FR, a positive camber (that is, a turning outer wheel) is provided on the rear wheels 2RL, 2RR on the turning outer wheel side. The camber angle having the opposite phase to the front wheels 2FL and 2FR is given (S18), and the camber giving process (S8) is ended. By providing this positive camber, the vehicle 1 can exert a force to rotate in the yaw direction, and the turning performance can be ensured.

  That is, in this case, the canvas last of the front wheels 2FL, 2FR on the turning outer wheel side to which the negative camber is applied acts on the vehicle 1 as a force for moving the front side portion of the vehicle 1 toward the turning inward, The rear wheels 2RL and 2RR on the turning outer wheel side to which the positive camber is applied act on the vehicle 1 as a force that moves the rear portion of the vehicle 1 toward the turning outward, so that the vehicle 1 is rotated in the yaw direction. This facilitates turning performance.

  On the other hand, in the process of S17, when it is determined that the lateral acceleration acquired in the process of S16 is equal to or greater than a predetermined value, that is, when it is determined that the lateral acceleration is equal to or larger than the reference value of the lateral acceleration (S17: Yes), Since the vehicle 1 is in an oversteer state where the vehicle turns with a turning radius equivalent to or smaller than the turning radius corresponding to the steering angle of the left and right front wheels 2FL, 2FR, it is considered that a large lateral load acts on the wheels 2, A negative camber is applied to the rear wheels 2RL and 2RR on the outer wheel side (S19), and this camber applying process (S8) is terminated. By giving this negative camber, turning performance can be ensured by making the wheels 2 (the rear wheels 2RL, 2RR on the turning outer wheel side difficult to slip).

  Next, a second embodiment will be described with reference to FIG. FIG. 6 is a schematic diagram schematically showing a top view of the vehicle 201 in the second embodiment. 6 corresponds to the schematic diagram of the vehicle 1 shown in FIG. However, in FIG. 6, illustration of unnecessary components is omitted in order to simplify the drawing and facilitate understanding.

  In the first embodiment, the case where the configuration (characteristics) of the tread of each wheel 2 is uniform in the width direction has been described, but the wheel 202 in the second embodiment has the first tread 221 and the first tread 221 having different characteristics. Two treads 222 are arranged side by side in the width direction. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment, and the description is abbreviate | omitted.

  In the vehicle 201 according to the second embodiment, the wheel 202 includes two types of treads, a first tread 221 and a second tread 222, and as shown in FIG. 6, each wheel 202 (front wheels 202FL, 202FR and rear wheels 2022RL). 202RR), the first tread 221 is disposed inside the vehicle 201, and the second tread 222 is disposed outside the vehicle 1.

  In the present embodiment, the width dimensions (dimensions in the left-right direction in FIG. 6) of both treads 221 and 222 are configured to be the same width dimension. In addition, the first tread 221 is configured to have a higher grip force (high grip performance) than the second tread 222. On the other hand, the second tread 22 is configured to have a characteristic of low rolling resistance (low rolling resistance) as compared to the first tread 21.

  In this case, the first tread 221 has a higher rolling resistance than the second tread 222 (high rolling resistance), and the second tread 22 has a grip force higher than that of the first tread 21. Low characteristics (low grip).

  When the camber angle of the wheel 202 is adjusted in the negative direction (negative camber) by the operation of the camber angle adjusting device 4, the ground contact area of the first tread 221 disposed inside the vehicle 201 is increased, and the vehicle 201 The ground contact area of the second tread 222 disposed outside is reduced. Thereby, the high grip performance of the first tread 221 can be used to improve the turning performance.

  On the other hand, when the camber angle of the wheel 202 is adjusted in the plus direction (positive camber direction) by the operation of the camber angle adjusting device 4, the ground contact area of the first tread 221 disposed inside the vehicle 201 is reduced. The contact area of the second tread 222 disposed outside the vehicle 201 is increased. Thereby, the low rolling resistance of the second tread 222 can be used to improve the fuel efficiency (fuel efficiency).

  Thus, in this Embodiment, since the wheel 2 is a structure provided with the 1st tread 221 and the 2nd tread 222, when it becomes necessary to ensure turning performance, as above-mentioned, as a turning outer ring | wheel By giving a negative camber to the front wheels 202FL, 202FR, etc. on the side (see S13 or S19 in FIG. 5), not only can the canvas last be exhibited to ensure turning performance, but in this case, Since the ground contact area on the 1 tread 221 side is increased, the gripping force of the wheel 202 to which the negative camber is applied can be secured correspondingly, and the turning performance can be further secured.

  On the other hand, when the vehicle is traveling straight or when the steering angles of the left and right front wheels 202FL and 202FR do not reach a predetermined value, the negative camber is not provided, and the contact area of the second tread 222 can be ensured accordingly. Therefore, rolling resistance can be reduced and fuel consumption performance can be improved.

  Even when it is necessary to ensure turning performance, the negative camber is applied to the front wheels 202FL, 202FR, etc. on the turning outer wheel side, and the front wheels 202FL, 202FR, etc. on the turning inner wheel side are provided. Since the negative camber is not provided, and the contact area of the second tread 222 can be secured correspondingly, the rolling resistance can be reduced and the fuel efficiency can be improved.

  Further, a positive camber (that is, a camber angle having a phase opposite to that of the front wheels 202FL and 202FR serving as the turning outer wheels) is imparted to the rear wheels 202RL and 202RR serving as the turning outer wheels, thereby exerting a force for rotating the vehicle 201 in the yaw direction. In this case (see S18 in FIG. 5), as described above, the rear wheels 202RL and 202RR on the turning outer wheel side are configured to move the rear portion of the vehicle 201 toward the turning outward (force in the same direction as the centrifugal force). ) Is applied to the vehicle 201, and therefore a grip force is relatively not required. Therefore, in this case, a positive camber is applied to the rear wheels 202RL and 202RR on the turning outer wheel side, and the contact area of the second tread 222 is increased, thereby reducing rolling resistance while ensuring turning performance. , Fuel efficiency can be improved.

  Here, in the flowchart shown in FIG. 4 (camber control process), the road surface state estimating means according to claim 1 corresponds to the processes of S1 to S7. Further, in the flowchart (camber applying process) shown in FIG. 5, the processing of S10 and S11 is performed as the traveling state determination means according to claim 1 or 5, and the processing of S13 is performed as the front wheel camber control means. The steering angle acquisition means is S10, the yaw rate acquisition means is part of S11, the turning state determination means is S10 and S11, and the yaw rate acquisition means according to claim 3 is S14. The process of S15 is the process of S15 as the yaw rate determination means, the processes of S18 and S19 as the rear wheel camber control means, the process of S16 as the lateral acceleration acquisition means according to claim 4, and the process of S16 as the lateral acceleration determination means. The process of S17 corresponds to each.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed.

  For example, the numerical values given in the above embodiments are merely examples, and other numerical values can naturally be adopted.

  In each of the above embodiments, if the operation angle or the like of the steering 63 of the vehicle 1 or 201 is not equal to or greater than a predetermined value in the processing of S10 or S11 shown in FIG. 5 (S10 or S11: Yes), the front wheel 2FL on the turning outer wheel side However, the present invention is not necessarily limited to this. For example, if at least the vehicle 1 is not traveling straight, the operation angle of the steering 63 of the vehicles 1 and 201 is predetermined. The camber angle may be applied to the front wheels 2FL, 2FR, etc. on the turning outer wheel side even if the value is not more than the value. As a result, the camber angle can be given to the wheel 2 in a prospective control unless the vehicles 1 and 201 are traveling straight ahead at least, and then an emergency sudden turn is performed. However, turning performance can be ensured without causing a response delay.

  Although description is omitted in each of the above-described embodiments, the road surface information on the route on which the vehicle 1,201 is scheduled to travel is acquired by the navigation device 82, and when the road surface information satisfies a predetermined condition, the turning outer wheel A camber angle may be given to the front wheels 2FL, 2FR on the side. As the predetermined condition, for example, when the route planned to travel is a curve with a predetermined radius or less, when the curve on the route planned to travel is a curve with a radius greater than or equal to the predetermined radius but downhill, the route planned to travel For example, the curve in FIG. 5 is a curve having a predetermined radius or more, but the friction coefficient is not more than a predetermined value. As a result, the camber angle can be given to the wheel 2 in a predictive manner before entering the curve, so that the turning performance can be ensured without causing a response delay.

  In each of the above embodiments, in the process of S4 of FIG. 4, it is determined whether the navigation information indicates north, that is, whether the current position of the vehicles 1 and 201 is north of the reference position (reference latitude). However, the present invention is not necessarily limited to this, and it may be determined whether other conditions are satisfied. Other conditions include, for example, a case where it is determined whether the current position of the vehicles 1 and 201 is located on the north side of a structure such as a building. That is, the road surface located on the north side of a structure such as a building is likely to be shaded and frozen.

  In each of the above embodiments, in the camber control process of FIG. 4, if it is estimated that the road friction coefficient is low in any one of the processes from S1 to S7 (that is, any one of S1 to S7). In the process, when the determination result is “Yes”), the case where the process of S8 is executed has been described. However, the present invention is not necessarily limited to this, and in at least two or more processes of S1 to S7, the friction coefficient of the road surface is When it is estimated that the value is low, the process of S8 may be executed. Thereby, since the estimation precision of the friction coefficient of a road surface can be raised, provision of the unnecessary camber angle to the wheels 2 and 202 can be suppressed. As a result, it is possible to suppress unnecessary increase in rolling resistance and improve fuel efficiency (fuel efficiency).

  In each of the above embodiments, the case where the camber angle applied to the wheels 2 and 202 in the processing of S13, S18 and S19 in FIG. 5 is a fixed value (for example, 5 degrees) has been described. Instead, the camber angle value given to the wheels 2 and 202 in the processing of S13, S18, and S19 in FIG. 5 may be changed according to the state of the vehicles 1 and 201 and the state of the road surface.

  Examples of the state of the vehicles 1, 201 include the traveling speed of the vehicles 1, 201, the operation angle of the steering 63, and examples of the road surface state include a friction coefficient of the road surface. That is, the camber angle given to the wheels 2, 202 in the processing of S13, S18 and S19 in FIG. 5 is changed according to these values (travel speed, operation angle, friction coefficient) (for example, in proportion). To do. Thereby, coexistence with ensuring of turning performance and improvement of fuel consumption performance can be aimed at more efficiently.

  In each of the above-described embodiments, S1 to S7 have been described as processing that is a condition for executing the camber grant processing (S8) in the camber control processing of FIG. 4, but the processing from S1 to S7 is an example. Of course, it is possible to use other processes. Examples of other processing include processing for determining whether the wheels 2 and 202 are slipping, processing for determining whether the vehicle speed of the vehicles 1 and 201 is equal to or higher than a predetermined value, and the like. The slip of the wheels 2 and 202 can be determined based on the detection result of the wheel rotation speed sensor device 35 (see FIG. 3) as described above.

It is the schematic diagram which showed typically the vehicle by which the vehicle control apparatus in 1st Embodiment of this invention is mounted. It is a front view of a suspension apparatus. It is the block diagram which showed the electric constitution of the control apparatus for vehicles. It is a flowchart which shows a camber control process. It is a flowchart which shows a camber provision process. It is the schematic diagram which showed typically the vehicle in 2nd Embodiment.

Explanation of symbols

100 Vehicle Control Device 1 Vehicle 2, 202 Wheel 2FL, 202FL Left front wheel (part of wheel)
2FR, 202FR Right front wheel (part of the wheel)
2RL, 202RL Left rear wheel (part of the wheel)
2RR, 202RR Right rear wheel (part of the wheel)
221 First tread 222 Second tread 44 Camber angle adjusting device 44FL FL actuator (part of camber angle adjusting device)
44FR FR actuator (part of camber angle adjusting device)
44RL RL actuator (part of camber angle adjustment device)
44RR RR actuator (part of camber angle adjustment device)
72a Yaw rate map (yaw rate reference value storage means)
72b Lateral acceleration map (lateral acceleration reference value storage means)

Claims (6)

A vehicle for use in a vehicle in which at least the front wheel is steered, comprising: left and right front wheels and left and right rear wheels; In the control device,
Traveling state determining means for determining whether the vehicle is turning;
Road surface state estimating means for estimating whether the friction coefficient of the road surface is lower than a predetermined value;
The camber angle adjusting device is activated when the road surface state estimating means estimates that the friction coefficient of the road surface is lower than a predetermined value and the running state determining means determines that the vehicle is turning. And a front wheel camber control means for providing a negative camber to the front wheel on the turning outer wheel side of the left and right front wheels. Steering angle acquisition means for acquiring the steering angle of the left and right front wheels;
A yaw rate acquisition means for acquiring a yaw rate of the vehicle;
Turning state determination means for determining whether the steering angle of the left and right front wheels acquired by the steering angle acquisition means is larger than a predetermined value or whether the yaw rate of the vehicle acquired by the yaw rate acquisition means is larger than a predetermined value. And comprising
The front wheel camber control means is estimated by the road surface state estimation means that the friction coefficient of the road surface is lower than a predetermined value, and the turning state determination means determines that the vehicle is turning, and The turning state determination means determines that the steering angle of the left and right front wheels acquired by the steering angle acquisition means is larger than a predetermined value, or the vehicle yaw rate acquired by the yaw rate acquisition means is larger than a predetermined value. 2. The vehicle control device according to claim 1, wherein the camber angle adjusting device is operated to apply a negative camber to the front wheel on the turning outer wheel side of the left and right front wheels. A yaw rate reference value storage means for storing a reference value of the yaw rate of the vehicle in association with a steering angle of the left and right front wheels;
Steering angle acquisition means for acquiring the steering angle of the left and right front wheels;
A yaw rate acquisition means for acquiring a yaw rate of the vehicle;
The yaw rate reference value corresponding to the steering angle of the left and right front wheels acquired by the steering angle acquisition means is read from the yaw rate reference value storage means, and is acquired by the yaw rate acquisition means from the read yaw rate reference value. Yaw rate determination means for determining whether the vehicle has a low yaw rate;
When the yaw rate determining means determines that the yaw rate of the vehicle is smaller than the reference value of the yaw rate, the camber angle adjusting device is operated to turn the rear wheel on the turning outer wheel side of the left and right rear wheels. The vehicle control device according to claim 1, further comprising rear wheel camber control means for applying a negative camber or a positive camber to the vehicle. Lateral acceleration reference value storage means for storing a reference value of the lateral acceleration of the vehicle in association with a steering angle of the left and right front wheels;
Lateral acceleration acquisition means for acquiring lateral acceleration of the vehicle;
The reference value of the lateral acceleration corresponding to the steering angle of the left and right front wheels acquired by the steering angle acquisition means is read from the lateral acceleration reference value storage means, and the acquisition means is more than the read lateral acceleration reference value. Lateral acceleration determining means for determining whether the acquired lateral acceleration of the vehicle is small,
The rear wheel camber control means, when the lateral acceleration judgment means judges that the lateral acceleration of the vehicle is smaller than a reference value of the lateral acceleration, A positive camber is applied to the rear wheel, and when it is determined that the lateral acceleration of the vehicle is larger than the reference value of the lateral acceleration, the rear wheel on the turning outer wheel side of the left and right rear wheels 4. The vehicle control device according to claim 3, wherein a negative camber is provided. In a vehicle control device used in a vehicle, including left and right front wheels and left and right rear wheels, and camber angle adjusting devices that independently adjust camber angles of the left and right front wheels and left and right rear wheels,
Traveling state determining means for determining whether the vehicle is turning;
Road surface state estimating means for estimating whether the friction coefficient of the road surface is lower than a predetermined value;
A yaw rate determining means for determining whether the yaw rate of the vehicle is greater than a predetermined value;
The camber angle adjusting device is activated when it is determined that the vehicle is turning by the traveling state determining unit and the road surface state estimating unit estimates that the friction coefficient of the road surface is lower than a predetermined value. And giving a camber angle to at least one of the left and right front wheels,
Further, when the yaw rate determining means determines that the yaw rate of the vehicle is smaller than a predetermined value, the camber angle adjusting device is operated to set a camber angle on at least one of the left and right rear wheels. A control apparatus for a vehicle characterized by providing The left and right front wheels and the left and right rear wheels include a first tread and a second tread having different characteristics from the first tread.
The first tread is configured to have a higher gripping property than the second tread, and the second tread is configured to have a lower rolling resistance than the first tread.
6. The ground contact area of the first tread is increased when the first tread is located inside the vehicle than the second tread and a negative camber is applied. Vehicle control device.

Images