JP2006335218A - Spoiler control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform suitable spoiler control by accurate monitoring of the ground-contact state of a wheel. <P>SOLUTION: Forward/rearward force F<SB>x</SB>, lateral force F<SB>y</SB>and vertical force F<SB>z</SB>applied to a tire are detected by a tire force sensor 8. In a friction circle utilization ratio calculation part 71, a friction circle utilization ratio R of the tire is calculated from the detected applying force. On an angle of elevation instruction map 74, an increased target angle of elevation of a rear spoiler is made corresponding to the increased friction circle utilization ratio of the tire. In a control amount setting part 73, the target angle of elevation θ of the rear spoiler 6 is set from the friction circle utilization ratio R calculated with reference to the angle of elevation instruction map 74. The rear spoiler 6 is driven by a spoiler drive part 75 according to the set target angle of elevation θ. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a spoiler control device that controls a spoiler mounted on a vehicle.

2. Description of the Related Art Conventionally, there has been known a device that adjusts a front spoiler protrusion amount, a rear spoiler elevation angle, and the like in order to prevent vehicle lift during high-speed traveling and stabilize traveling. The lift control device described in Patent Document 1 is an example of such a device. In this lift control apparatus, the protrusion amount of the front spoiler mounted on the vehicle and the elevation angle of the rear spoiler (rear wing) are adjusted based on the state of the ground load of the front and rear wheels. Specifically, the lateral force or vertical force applied to the suspension (suspension device) is the lateral force or vertical force acting on the wheel, and the ground contact state of the vehicle is determined based on this acting force. For example, when the vertical force applied to the suspension of the front wheels is small, it is determined that the ground load on the front wheels is small. In order to increase the ground load and raise the down force, the front spoiler is controlled so that the protrusion amount is increased.
JP-A-3-579

  However, in this lift control device, since the force acting on the suspension is regarded as the force acting on the wheels, it cannot be said that the ground contact load of the vehicle is accurately detected. This is because the force acting on the suspension is a force generated with a change in the posture of the vehicle body, so this acting force and the force actually acting on the wheel differ in value, and the timing at which the acting force of the suspension changes further This is because there is a delay from the change in the acting force of the wheels.

  An object of the present invention is to ensure proper spoiler control by accurately monitoring the ground contact state of a wheel.

  In order to solve this problem, the present invention provides a spoiler control device for controlling a spoiler mounted on a vehicle. The spoiler control device includes a tire force sensor, a control amount setting unit, and a spoiler drive unit. The acting force acting on the tire is detected by the tire force sensor. Based on the detected acting force, the control amount setting unit sets the control amount of the spoiler. Further, the spoiler is driven by the spoiler drive unit according to the set control amount.

  In this invention, it is preferable to have a utilization rate calculation part and to make a tire force sensor and an elevation angle setting part as follows. In the tire force sensor, longitudinal force, lateral force, and vertical force are detected as the acting force. The utilization factor calculation unit calculates the friction circle utilization factor of the tire based on the detected longitudinal force, lateral force, and vertical force. The control amount setting unit is calculated by the utilization rate calculation unit based on the first map in which the target elevation angle, which is the control amount of the spoiler, is increased with respect to the increasing tire friction circle utilization rate. The target elevation angle is set from the friction circle utilization rate.

  In the present invention, the tire force sensor and the control amount setting unit may be configured as follows. A vertical force is detected as an acting force by the tire force sensor. In the control amount setting unit, from the vertical force detected by the tire force sensor based on the second map in which the target elevation angle, which is the control amount of the spoiler, is decreased with respect to the increasing vertical force of the tire. A target elevation angle is set.

  In the present invention, the tire force sensor and the control amount setting unit can be configured as follows. A longitudinal force is detected as an acting force by the tire force sensor. In the control amount setting unit, from the longitudinal force detected by the tire force sensor based on the third map in which the target elevation angle, which is the control amount of the spoiler, is decreased with respect to the increasing tire longitudinal force. A target elevation angle is set.

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In this invention, it is preferable that the apparatus further includes a speed sensor, an acceleration sensor, a lateral acceleration sensor, and a running state determination unit, and the control amount setting unit is as follows. The speed of the vehicle is detected by the speed sensor, the acceleration in the longitudinal direction of the vehicle is detected by the acceleration sensor, and the acceleration in the lateral direction of the vehicle is detected by the lateral acceleration sensor. The traveling state determination unit determines the traveling state of the vehicle based on the detected vehicle speed and the acceleration in the front-rear direction and the lateral direction of the vehicle. In the control amount setting unit, when the vehicle decelerates straight as a result of the determination by the traveling state determination unit, a larger target elevation angle is set than when the vehicle turns or accelerates.

  In the present invention, since the acting force of the wheel (tire) is directly detected by the tire force sensor, the accuracy of the value is high. Therefore, by controlling the spoiler based on the detected value, it is possible to perform more preferable appropriate control according to the ground contact state of the vehicle.

(First embodiment)
FIG. 1 is a diagram for explaining a schematic configuration of a vehicle on which the spoiler control device 7 according to the first embodiment is mounted, and FIG. 2 is an explanatory diagram for forces acting on the wheels 5.

  As shown in FIG. 1, the vehicle is a four-wheel drive vehicle, and all four wheels, front, rear, left and right, are driven. The power of the engine 1 is transmitted to the front and rear axles 4 through the automatic transmission 2, the center differential 3a, the front differential 3b, the rear differential 3c, and the like. By transmitting this power to the axle 4, driving torque is applied to the left and right front wheels 5fl, 5fr and the left and right rear wheels 5rl, 5rr, and each wheel 5 is driven. The four-wheel drive vehicle is provided with a rear spoiler 6 at the rear of the vehicle in order to stabilize traveling during acceleration / deceleration and turning. The rear spoiler 6 includes a left rear spoiler 6a disposed on the left side and a right rear spoiler 6b disposed on the right side with respect to the vehicle center, and these are controlled independently by the spoiler control device 7.

Tire force sensors 8fl, 8fr, 8rl, 8rr are provided inside the axle 4 in the vicinity of the wheels 5fl, 5fr, 5rl, 5rr. Each tire force sensor 8 detects longitudinal force F _x , lateral force F _y , and vertical force F _z acting on the tire. As shown in FIG. 2, the longitudinal force F _x is about frictional force generated in the ground surface of the tire to cover the outer periphery of the wheel 5, a component force in a direction parallel to the wheel center plane (x-axis direction), lateral force F _y is a component force in a direction perpendicular to the wheel center plane (y-axis direction). The vertical force _Fz is a ground load acting in the vertical direction (z-axis direction).

Each of the tire force sensors 8 (FIG. 1) includes a strain gauge and a signal processing circuit that processes the output electric signal to generate a detection signal. Since the stress generated in each axle 4 is proportional to the force acting on each corresponding tire, the stress in the x-axis, y-axis, and z-axis directions is detected by a strain gauge embedded in the axle 4, respectively. The longitudinal force F _x , the lateral force F _y , and the vertical force F _z are directly detected. For example, Japanese Patent Laid-Open Nos. 04-331336 and 10-318862 describe a more specific configuration of the tire force sensor 8. The tire force sensor 8 may be provided on a member that holds the wheel 5 such as a hub or a hub carrier. Japanese Patent Application Laid-Open No. 2003-104139 describes the provision of the tire force sensor 8 on a hub.

A wheel speed sensor 9fl, 9fr, 9rl, 9ff is provided for each of the wheels 5fl, 5fr, 5rl, 5rr, and the wheel speed v of each wheel 5 is detected. The individually detected wheel speed v is used to calculate the vehicle speed (vehicle speed). The acceleration sensor 10a detects an acceleration a _x in the longitudinal direction of the vehicle, on the basis of the detected value, whether the vehicle is traveling with acceleration or deceleration, determining the running state whether running steadily at a constant rate Is possible. The lateral acceleration sensor 10b can detect the acceleration a _y in the lateral direction of the vehicle and determine the traveling state based on the detected value as to whether or not the vehicle is turning.

  FIG. 3 is a diagram for explaining the operation of the rear spoiler 6, and FIG. 4 is a block diagram showing a main configuration of the spoiler control device 7.

As shown in FIG. 3, the spoiler control device 7 can adjust the elevation angles of the left rear spoiler 6a and the right rear spoiler 6b independently of each other. The elevation angle is an angle θ formed by the rear spoilers 6a and 6b with reference to a straight line L parallel to the longitudinal direction of the vehicle body (the horizontal direction in the figure). Here, the elevation angles of the left rear spoiler 6a and the right rear spoiler 6b are adjusted to θ _a and θ _b , respectively. As the rear spoiler 6 stands up (rotates counterclockwise in the figure) and the elevation angle of the rear spoiler 6 increases, the downforce that acts in the negative direction of the z-axis and the x-axis respectively as a resistance force acting on the rear spoiler 6 and the vehicle body. α and air resistance ε increase.

These down force α and air resistance ε are forces acting directly on the vehicle body, but are transmitted to the wheel 5 and affect the vertical force F _z and the longitudinal force F _x , respectively. When the vehicle is traveling at a constant acceleration, the vertical force F _z increases as the down force α acting downward increases, and the vertical force F _z decreases as the down force α decreases. Further, the longitudinal force F _x increases as the air resistance ε acting backwards increases.

  As shown in FIG. 4, the spoiler control device 7 mainly includes a friction circle utilization rate calculation unit 71, a traveling state determination unit 72, a control amount setting unit 73, and a spoiler drive unit 75, and various sensors 8. Based on the detected value of -10, control for reducing the elevation angle of the rear spoiler 6 during acceleration is performed. The spoiler control device 7 mainly includes a microcomputer having a CPU, a ROM, a RAM, an input / output interface, and the like, and the friction circle utilization rate calculation unit 71, the running state determination unit 72, and the control amount setting unit 73 include the microcomputer. It corresponds to the control program on the ROM executed in The spoiler drive unit 75 is a known actuator including a motor and the like.

The outline of the function of each part 71-73 which comprises a control program is as follows. In the friction circle utilization factor calculation unit 71, the tire friction circle utilization factor R (described later) is based on the acting force of the tire such as the longitudinal force F _x , lateral force F _y , and vertical force F _z detected by the tire force sensor 8. ) Is calculated. In the traveling state determination unit 72, the wheel speed v detected by the wheel speed sensor 9 (or the vehicle speed calculated from the wheel speed v, the vehicle speed detected by the vehicle speed sensor), and the acceleration a detected by the acceleration sensor 10a. The running state of the vehicle is determined based on _x and the lateral acceleration _ay detected by the lateral acceleration sensor 10b. In the control amount setting unit 73, the target elevation angle θ is read and set from the elevation angle instruction map 74 in accordance with the traveling state of the vehicle. A control signal corresponding to the target elevation angle θ set in this way is output to the spoiler drive unit 75, and the drive of the rear spoilers 6a and 6b is controlled.

The main feature of the spoiler control device 7 is the control of an appropriate spoiler based on the longitudinal force F _x , the lateral force F _y , and the vertical force F _z detected by the tire force sensor 8. This spoiler control process will be described in detail. . FIG. 5 is a flowchart illustrating a procedure of spoiler control processing that is called and executed at predetermined time intervals in the spoiler control device 7. FIG. 6 is an elevation angle instruction map 74 showing the correspondence relationship between the friction circle utilization rate R and the target elevation angle θ referred to in step 6 of the spoiler control process.

In step 1, first, detected values of the longitudinal force F _x , lateral force F _y and vertical force F _z of the wheel 5 by the tire force sensor 8 are read. In step 2, the following Equation 1, loaded longitudinal force F _{x, the} lateral force F _y, and, from the vertical force F _z, the left and right rear wheels 5rl, the friction circle utilization R for 5rr is calculated.

Here, μ _p is the maximum coefficient of friction that can occur between the wheel 5 and the ground contact surface. This friction circle utilization rate R is the ratio of the actual friction force that is the resultant force of the longitudinal force F _x and the lateral force F _y to the maximum friction force that is the product of the friction coefficient μ _p and the vertical force F _z, and is 0 Takes a value between 1 and 1. In other words, the friction circle utilization rate R of the wheel 5 indicates the frictional force that can be generated by the wheel 5, that is, the remaining force of the driving force, and the larger the friction circle utilization rate R approaches 0, the larger the remaining force. The closer the friction circle utilization rate R is to 1, the smaller the remaining power.

In step 3, the left and right rear wheels 5rl, for 5rr, the current value R _n of the calculated friction circle utilization of friction utilization ratio when calculated in the previous processing value R _n-1 (hereinafter previous value R _n-1 ). Left and right rear wheels 5rl, for 5rr, smaller than the determination value R _th difference none is given the current value R _n and previous value R _n-1 (Yes at Step 3), this processing is ended. If any of the differences is larger than determination value _Rth (No in step 3), the target elevation angles of rear spoilers 6a and 6b are set by the processing in steps 4-6.

In step 4, detection values by the wheel speed sensor 9, the acceleration sensor 10a, and the lateral acceleration sensor 10b are read. In step 5, based on these detected values, the running state of the vehicle, such as whether the vehicle is accelerating / decelerating or turning, is determined. If the result of this determination is that the vehicle is accelerating traveling or turning in step 6, the curve L ₁ in elevation instruction map 74 shown in FIG. 6 is referred to selectively, left rear spoiler 6a and right rear spoiler 6b And the target elevation angle are set respectively. Further, the result of the determination in Step 5, when the vehicle is (straight) deceleration traveling, in step 6, the curve L ₂ is referred to selectively, the rear spoiler 6a, the target elevation angle and 6b is set. In step 7, the rear spoilers 6a and 6b are driven in accordance with the set target elevation angle, and the present process ends.

In the elevation angle instruction map 74 referred to, a target elevation angle θ appropriate for the friction circle utilization rate R is set in advance. Curve L ₁ represents the correspondence between the friction circle utilization R and the target elevation angle θ during acceleration and turning of the vehicle, the curve L ₂ shows the relationship at the time of deceleration. During deceleration (curve L ₂ ), a larger target elevation angle θ is set than when accelerating or turning (curve L ₁ ). With such a setting, the air resistance ε of the rear spoiler 6 at the time of deceleration becomes larger than that at the time of acceleration or turning, and the longitudinal force F _x of all the wheels 5 at the time of deceleration is further reduced by this air resistance ε. As a result, the braking distance of the vehicle can be shortened, and the burden on the braking device such as a brake can be reduced.

The contents of the experiment or simulation for creating this elevation angle instruction map 74 will be described in more detail. The correspondence between the friction circle utilization rate R and the target elevation angle of the rear spoiler 6 can be determined based on measuring the downforce α and the air resistance ε acting on the vehicle with respect to the elevation angle that is arbitrarily changed. Similarly, with respect to the correspondence relationship between the vertical force F _z and the longitudinal force F _x shown in FIGS. 8 and 9 described later and the target elevation angle of the rear spoiler 6, the down force α and the air resistance ε are measured with respect to the elevation angle of the rear spoiler 6. Can be determined based on

A down force α acting as a resistance force in the z-axis direction on the vehicle body during traveling is calculated by the following formula 2.

Here, m represents the mass of the vehicle, and g represents the gravitational acceleration. Downforce α is as shown here, the vertical force F _{Fl_z} acting on each wheel 5 detected by the tire force sensor _8, F fr_z, F rl_z, from the sum of F _{Rr_z,} minus the weight of the vehicle when stopped Value. The acting force acting on the wheel 5 is distinguished for each wheel by the subscripts fl, fr, rl, and rr. Subsequent subscripts x, y, and z are used to distinguish the front and rear, lateral and vertical directions of the component force.

Further, the air resistance ε acting as a resistance force in the x-axis direction on the vehicle body is calculated by Equation 3.

That is, the air resistance epsilon, longitudinal force F _{Fl_x} acting on each wheel 5 detected by the tire force sensor _8, F fr_x, F rl_x, acceleration from the sum of F _{Rr_x,} detected by the vehicle mass m and the acceleration sensor 10a It is calculated as a value obtained by subtracting the product of a _x.

  The down force α and the air resistance ε calculated in this way are calculated based on the detected value of the applied force (and the use of the friction circle calculated from them) while considering how much the applied force of the wheel 5 is adjusted during traveling. Rate R). Thereby, a highly accurate elevation angle instruction map 74 is created, and by setting the target elevation angle θ using such a correspondence map, spoiler control can be performed accurately and appropriately.

By the processing up to step 6 described above, the target elevation angle is actually set as shown in Table 1 for each of (1) acceleration traveling, (2) deceleration traveling, and (3) turning traveling.

  Table 1 will be supplemented. As a method of determining the sign of the longitudinal force, acceleration is positive and deceleration is negative. For this reason, during deceleration, the value of the longitudinal force (including positive and negative) decreases, but the absolute value increases. Further, as a method for determining the sign of the lateral force, the left turn (left direction) is positive, and the right turn (right direction) is negative. For this reason, although the absolute value of the lateral force during turning increases, the value differs between left turn and right turn. That is, the value increases when turning left and decreases when turning right.

(1) at the time of acceleration, the longitudinal force F _{Fl_x} of all wheels _{5, F fr_x, F rl_x,} F rr_x increases. Vertical force F _{Rl_z} of the left and right rear wheels, F _{Rr_z} increases, the left and right front wheels of the vertical force _F fl_z, F fr_z decreases. According to this, from equation 1 described above, the left and right rear wheels 5rl, that the current value R _n of the friction circle utilization R of 5rr is smaller than the previous value R _n-1 can be confirmed. According to yet a curve L ₁ indicating the correspondence during acceleration in elevation instruction map 74 of FIG. 6, the left and right rear wheels 5rl friction utilization ratio R becomes smaller, the target elevation angle of the corresponding rear spoiler 6a, 6b in 5rr, more It will be set to a small value. The rear spoilers 6a and 6b are driven according to the target elevation angle.

Acceleration of the left and right front wheels 5fl, for friction circle utilization R of 5fr, likewise, it is understood that the current value R _n from Equation 1 becomes larger than the previous value R _n-1. When the elevation angles of the rear _spoilers 6a and 6b are reduced as described above, the vertical forces _{Frl_z} and _{Frr_z} of the left and right rear wheels become smaller, and the vertical forces _{Ffl_z} and _{Ffr_z} of the left and right front wheels become larger. As a result, the friction circle utilization rate R of the left and right rear wheels 5rl and 5rr is larger, and the friction circle utilization rate R of the left and right front wheels 5fl and 5fr is smaller.

According to this, during acceleration, the rear spoiler 6a, by reducing the elevation of 6b, by changing the vertical force F _z of the front and rear left and right wheels, the left and right front wheels 5fl, 5fr the friction circle utilization R and the left and right rear wheels 5rl, 5rr Thus, the balance with the friction circle utilization rate R is maintained, and the running stability during acceleration is improved.

(2) Conversely, during deceleration, the longitudinal force F _{Fl_x} wheels _{5, F fr_x, F rl_x,} F rr_x decreases (although larger absolute value). Vertical force F _{Rl_z} of the left and right rear wheels, F _{Rr_z} decreases, the left and right front wheels of the vertical force _F fl_z, F fr_z increases. From Equation 1 described above, the left and right rear wheels 5rl, the current value R _n of the friction circle utilization R of 5rr becomes larger than before value R _n-1. According to the curve L ₂ in the map of FIG. 6, the friction utilization ratio R Gayori larger rear wheels 5rl, the rear spoiler 6a, the target elevation angle and 6b corresponding to 5rr is set to a larger value.

Deceleration of the left and right front wheels 5fl, for friction circle utilization R of 5fr, likewise, the current value R _n becomes smaller than the previous value R _n-1 from Equation 1. Rear spoiler 6a, when the elevation angle of 6b is increased as described above, the vertical force F _{Rl_z} of the left and right rear wheels, F _{Rr_z} more with larger left and right front wheels of the vertical force _F fl_z, F fr_z becomes smaller. As a result, the friction circle utilization rate R of the left and right rear wheels 5rl and 5rr becomes smaller, and the friction circle utilization rate R of the left and right front wheels 5fl and 5fr becomes larger.

According to these, during deceleration, the rear spoiler 6a, by increasing the elevation of 6b, by changing the vertical force F _z of the front and rear left and right wheels, the left and right front wheels 5fl, 5fr the friction circle utilization R and the left and right rear wheels 5rl, 5rr The balance with the friction circle utilization rate R is maintained, and the running stability during deceleration is improved.

(3) at the time of turning, the lateral force F _{Fl_y} wheels _5, F fr_y, F rl_y, the absolute value of F _{Rr_y} increases (however, the values including positive and negative, increases during left turning, decreases during right turning ). Further, the vertical force F _z of the wheels 5 of the inner ring is smaller than the vertical force F _z of the wheels 5 of the outer ring side. From Equation 1 above, the inner ring of the friction circle utilization rate R is the current value R _n becomes larger than before value R _n-1, the friction circle utilization R of the outer ring, the current value R _n previous value R _n-1 Smaller than. According to the map of the curve L ₁ in FIG. 6, the friction utilization ratio R corresponds to the inner ring after the increase, one goal elevation of the left rear spoiler 6a and right rear spoiler 6b is set to a larger value. The target elevation angle of the other rear spoiler 6 corresponding to the rear outer wheel where the friction assistance rate R becomes smaller is set to a smaller value.

During the turning, by setting the elevation angle as described above, by controlling the driving of the rear spoiler 6a, 6b, together with the vertical force F _z of the outer ring becomes smaller, larger inner ring of vertical force F _z Gayori. As a result, the friction ring utilization rate R of the outer ring becomes larger, and the friction circle utilization rate R of the inner ring becomes smaller.

According to this, when turning, the elevation angle of the rear spoiler 6 corresponding to the inner wheel is increased, the elevation angle of the rear spoiler 6 corresponding to the outer wheel is decreased, and the vertical force F _z of the front and rear left and right wheels is changed to change the front and rear left wheels 5fl. , 5rl of the friction circle utilization rate R and the friction circle utilization rate R of the front and rear right wheels 5fr, 5rr are maintained, and the running stability during turning is improved.

According to the spoiler control device 7 according to the present embodiment, the friction circle utilization rate R calculated using the longitudinal force F _x , the lateral force F _y and the vertical force F _z detected by the tire force sensor 8 (FIG. 4). The target elevation angle of the rear spoiler 6 is set based on the vehicle traveling state such as acceleration / deceleration and turning detected by the wheel speed sensor 9, the acceleration sensor 10a and the lateral acceleration sensor 10b. For this reason, the rear spoiler 6 can be appropriately controlled in accordance with various grounding states and traveling states of the vehicle. Further, since the tire force sensor 8 directly detects the longitudinal force F _x , the lateral force F _y and the vertical force F _z acting on the tire, it detects the force acting on the suspension as in the conventional case and applies it to the wheel. Rather than using it as a working force, the ground contact state of the wheel 5 can be determined with high accuracy and responsiveness.

  The spoiler control performed based on the direct detection of the acting force of the wheels 5 has high operation reliability. In particular, since the friction circle utilization rate is calculated and the rear spoiler 6 is controlled based on the calculated value, the wheels 5 can be driven within a range in which the vehicle 5 does not cause a side slip or the like, and the running stability can be reliably ensured.

  In the spoiler control device 7 of the present embodiment, the rear spoiler 6 provided at the rear of the vehicle is controlled. For example, a plurality of spoilers attached to the front, side, and upper portions of the vehicle are controlled. Also good. Moreover, the front structure etc. which the lift control apparatus described in Unexamined-Japanese-Patent No. 3-579 controls also about the detailed structure can be assumed. Furthermore, various variations can be considered for the mounting form of the spoiler. In particular, when a spoiler is provided corresponding to each of all the wheels 5 and each spoiler is controlled according to the control method described above, the grounding property of each wheel 5 is improved.

The method for detecting acceleration is not limited to the method using the acceleration sensor 10a and the lateral acceleration sensor 10b. For example, like the wheel speed sensor 9 detects the vehicle speed, the variation in the vehicle speed per unit time may be detected as the acceleration a _x. Further, since the lateral acceleration sensor 10b tends to include an error component due to roll motion, the lateral acceleration actually occurring in the vehicle based on the detected value by the lateral acceleration sensor 10b and the roll characteristics of the vehicle obtained in advance. The acceleration a _y may be specified. The turning state may be determined using a steering angle sensor that detects the steering angle of the wheel 5 instead of the lateral acceleration sensor 10b.

(Second Embodiment)
In the spoiler control device according to the second embodiment, unlike the spoiler control device 7 according to the first embodiment, the friction circle utilization rate R is not calculated, and the target of the rear spoiler 6 is based on the vertical force F _z of the wheel 5. The elevation angle is set. Various sensors 8 to 10 are connected to the spoiler control device in the same manner as the spoiler control device 7 of the first embodiment shown in FIG. 1. Other configurations, operations, effects, and the like are not described below. Same as spoiler control device 7.

FIG. 7 is a flowchart showing the procedure of spoiler control processing that is called and executed at predetermined time intervals in the spoiler control device. In step 1, the vertical force F _z detected by the tire force sensor 8 is read. In step 2, the detected vertical force F _{z — n} (current value) is compared with the vertical force F _{z — n−1} (previous value) detected in the previous execution. Left and right rear wheels 5rl, for 5rr, smaller than the determination value F _th Any difference is given between the current value F _{Z_n} and previous value _{F z_n-1} (Yes at step 2), this processing is ended. If any of the differences is larger than determination value F _th (No in step 2), the target elevation angles of rear spoilers 6a and 6b are set by the processing in steps 3 to 5, and the set target elevation angle in step 6 is set. In response to this, the driving of the rear spoiler 6 is instructed to the spoiler driving unit. Here, the setting process of the target elevation angle according to the map in step 5 is different from that of the spoiler control device 7 and will be described.

FIG. 8 is a map showing the correspondence between the vertical force F _z and the target elevation angle of the rear spoiler 6 referred to in step 5. Also in this correspondence map, an appropriate target elevation angle θ is set for the vertical force F _z from experiments and simulations. Curve L ₃ represents a relationship during acceleration and turning of the vehicle, the curve L ₄ are shows the corresponding relationship during deceleration. The target elevation angle of the rear spoiler 6 is set with reference to this map.

According to the spoiler control device of the present embodiment, the target elevation angle of the rear spoiler 6 is set based on the vertical force F _z acting on the tire detected more directly by the tire force sensor 8. Appropriate spoiler control can be performed with a simpler configuration.

(Third embodiment)
In the spoiler control device of the third embodiment, in particular, the target elevation angle θ is set based on the longitudinal force F _x instead of the vertical force _{z of the} wheel 5. Further, it is determined whether or not the vehicle is in a straight line at a high speed and at a constant speed. When the vehicle is traveling at a high speed, the driving of the rear spoiler 6 is controlled so that the elevation angle is suitable for this. Is done. Various sensors 8 to 10 are connected to the spoiler control device in the same manner as the spoiler control device 7 in FIG. 1, and control similar to the spoiler control processing shown in FIG. 7 is performed. Other configurations, operations, effects, and the like conform to the spoiler control device 7 except for the following description.

In step 2 of the spoiler control process in FIG. 7, the detected longitudinal force F _{x — n} (current value) is compared with the longitudinal force F _{x — n−1} (previous value) detected in the previous execution. If the left and right rear wheels 5rl, either the difference between the current value F _{x_n} and previous value F _{x_n} for 5rr is greater than the predetermined value F _th (No at step 2), in step 4, various in Step 3 Based on the detection values of the sensors 8 to 10, it is determined whether or not the vehicle is traveling in a straight high-speed steady state in addition to whether the vehicle is accelerating / decelerating or turning. Specifically, in each wheel 5, the longitudinal force F _x is substantially constant at a predetermined threshold value or more, the lateral force F _y is substantially zero, and the vertical force F _z acts uniformly and similarly. When the value is taken, it is determined that the vehicle is traveling in a straight high-speed steady state. Further, the vehicle speed detected by the wheel speed sensor 9 is substantially constant at a predetermined threshold value or more, and the acceleration a _x detected by the acceleration sensor 10a and the lateral acceleration a _y detected by the lateral acceleration sensor 10b are almost equal. When it is 0, it may be determined that the vehicle is in a straight high-speed steady running.

If it is determined in step 4 that the vehicle is traveling in a straight high-speed steady state, the target elevation angle θ corresponding to the longitudinal force F _x is set in step 5, and in step 6 the target elevation angle θ is set. Further, the driving of the rear spoiler 6 is instructed to the spoiler driving unit.

Figure 8 is referred to in step 5 of the spoiler control processing, a map showing the correspondence relationship between the target elevation angle of the longitudinal force F _x and the rear spoiler 6. Similar to the curves L _{1 to} L ₄ on the two maps described above, the curve L 5 is specified through experiments and simulations.

Here, in accordance with the longitudinal force F _x of the wheels 5 is increased, the target elevation angle of smaller value is set. This is because the air resistance ε acting on the vehicle increases as the longitudinal force F _x increases, so that this can be suppressed. As described above, when the increase in the air resistance ε is suppressed during the straight high-speed steady traveling, the fuel efficiency of the vehicle can be improved accordingly.

Explanatory drawing of the vehicle to which the spoiler control device 7 of the first embodiment is applied. Explanatory drawing of force acting on wheel 5 Illustration of the function of the rear spoiler 6 The block diagram which shows the main structures of the spoiler control apparatus 7 Flow chart showing the procedure of spoiler control processing Map showing correspondence between friction circle utilization rate R and target elevation angle θ of rear spoiler 6 The flowchart which shows the procedure of the spoiler control processing in the spoiler control apparatus of 2nd Embodiment. A map showing the correspondence between the vertical force F _z and the target elevation angle θ of the rear spoiler 6 A map showing the correspondence between the longitudinal force F _x of the spoiler control device of the third embodiment and the target elevation angle θ of the rear spoiler 6.

Explanation of symbols

1 Engine 2 Automatic transmission 3a Center differential 3b Front differential 3c Rear differential 4 Axle 5fl, fr, rl, rr Wheel 6 Rear spoiler 6a Left rear spoiler 6b Right rear spoiler 7 Spoiler control device 8fl, fr, rl, rr Tire force sensor 9fl, fr, rl, rr Wheel speed sensor 10a Acceleration sensor 10b Lateral acceleration sensor 71 Friction circle utilization rate calculation unit 72 Running state determination unit 73 Control amount setting unit 74 Elevation angle instruction map 75 Spoiler drive unit

Claims (5)

In a spoiler control device that controls a spoiler mounted on a vehicle,
A tire force sensor for detecting an acting force acting on the tire;
Based on the acting force detected by the tire force sensor, a control amount setting unit for setting a control amount of the spoiler,
A spoiler control device comprising a spoiler drive unit that drives a spoiler according to the control amount set by the control amount setting unit. The tire force sensor detects longitudinal force, lateral force and vertical force as the acting force,
Based on the longitudinal force, lateral force, and vertical force detected by the tire force sensor, it further includes a utilization rate calculating unit that calculates a friction circle utilization rate of the tire,
The said control amount setting part is based on the 1st map with which the target elevation angle which is the control amount of the said spoiler which is increased with respect to the tire friction circle utilization rate which increases is based on the said utilization rate calculation part. The spoiler control device according to claim 1, wherein the target elevation angle is set from the friction circle utilization rate calculated by: The tire force sensor detects vertical force as the acting force,
The control amount setting unit is detected by the tire force sensor based on a second map that is associated with a target elevation angle that is a control amount of the spoiler that decreases with respect to the vertical force of the tire that increases. The spoiler control device according to claim 1, wherein the target elevation angle is set from the vertical force. The tire force sensor detects a longitudinal force as the acting force,
The control amount setting unit is detected by the tire force sensor based on a third map that is associated with a target elevation angle that is a control amount of the spoiler that decreases with respect to the longitudinal force of the tire that increases. The spoiler control device according to claim 1, wherein the target elevation angle is set from the longitudinal force. A speed sensor for detecting the speed of the vehicle;
An acceleration sensor for detecting acceleration in the longitudinal direction of the vehicle;
A lateral acceleration sensor that detects lateral acceleration of the vehicle;
Based on the vehicle speed detected by the speed sensor, the longitudinal acceleration of the vehicle detected by the acceleration sensor, and the lateral acceleration of the vehicle detected by the lateral acceleration sensor. A traveling state determination unit that determines the traveling state of
The control amount setting unit sets a larger target elevation angle when the vehicle decelerates straight ahead as a result of the determination by the traveling state determination unit than when the vehicle turns or accelerates. The spoiler control device described in any of the above.

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