JP2007240392A - Ground load estimation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ground load estimation device, capable of estimating a ground load of a vehicle to employ for vehicle motion control with satisfactory accuracy in various motional states. <P>SOLUTION: An ECU 9 is constituted of a camber angle calculation section 42; a roll angle calculation angle 43; and a ground load calculation section 44; and the ground load estimating device 40 is constituted of the ECU 9, a laser distance sensor 11, a damper stroke sensor 12, a tire air pressure sensor 13, a steering angle 14, and a vehicle sensor 15. When the ground load calculation section 44 calculates tire displacement quantity for estimating a ground load W, the camber angle calculation section 42 and the roll angle calculation section 43 calculate the camber angle and the roll angle from a detection result of a damper stroke quantity, to employ for correction of the tire displacement quantity. Similarly, the tire displacement quantity is corrected, by employing the detection result of a tire air pressure and the detection result of a vehicle speed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a ground load estimation device for estimating a ground load of a vehicle, and more particularly to a technique for performing correction based on detection results by various detection means in calculating the ground load.

  The ground contact load of each wheel of the automobile varies depending on the driving situation. For example, the contact load of the outer wheel increases during turning, the contact load of the rear wheel increases during acceleration, and the contact load of the front wheel increases during deceleration. On the other hand, the grip force of the tire increases as the grounding load increases. For example, the right rear wheel grip force increases during left turn acceleration and exerts excellent turning ability by applying a large driving force to the right rear wheel. be able to. In addition, it is possible to obtain excellent driving performance and braking performance by grasping the ground contact load during acceleration and braking of the vehicle. Therefore, when performing vehicle motion control or the like, it is an important issue to accurately grasp the contact load of each wheel.

As a device for estimating the ground contact load of a wheel, there is a tire load estimating device for fixing a distance detecting means for detecting a distance to a road surface on a member such as an axle that moves up and down together with the wheel, and calculating a deflection of the tire from the detected distance. is there. In such a tire load estimation device, in order to improve the reliability, when one of the detection results of the longitudinal acceleration sensor and the lateral acceleration sensor falls outside the predetermined range, the distance measurement result is not used and both are detected. There has been proposed a tire monitoring device that obtains the deflection of a tire from a distance measurement result when the result is within a predetermined range (see Patent Document 1). This tire monitoring apparatus determines whether or not the load calculated from the deflection of the tire is within a target range defined based on the vehicle speed and the load.
JP-A-10-115578

  However, in the conventional tire monitoring device, only when the lateral acceleration and the longitudinal acceleration of the vehicle are within a predetermined narrow range, the tire deflection is obtained, and it is only determined whether the deflection amount is within the predetermined range. . For this reason, bending is required only when the vehicle travels straight with little acceleration / deceleration, and the detection result cannot be used for vehicle motion control that performs control in any motion state. In addition, when calculating the ground load from the deflection of the tire, if the distance detection result obtained by detecting the distance from the axle or other member to the road surface is used as it is, there is a problem that the reliability of the ground load estimation accuracy becomes low. .

  The present invention has been made in view of such a background, and provides a ground load estimation device capable of estimating a ground load of a wheel with sufficient accuracy to be used for vehicle motion control in any motion state. With the goal.

  In order to solve the above-mentioned problem, the invention according to claim 1 is installed on a wheel side member that moves up and down together with a wheel, and based on a distance detection means for detecting a distance to a road surface, and a detection result of the distance detection means, In a ground load estimation device including a ground load calculation means for calculating a ground load of the wheel as a ground load estimated value, a stroke amount of a damper interposed between the wheel side member and a vehicle body side member is detected. And further comprising: a damper stroke amount detecting means; and a camber angle calculating means for calculating a camber angle based on a detection result of the damper stroke amount detecting means, wherein the contact load calculating means is based on a calculation result of the camber angle calculating means. And providing a ground load estimation device that corrects the distance.

  The invention according to claim 2 is provided on a wheel side member that moves up and down together with the wheel, and based on the detection result of the distance detection means and the distance detection means for detecting the distance to the road surface, A contact load estimating device comprising a contact load calculating means for calculating a contact load estimated value; a damper stroke amount detecting means for detecting a stroke amount of a damper interposed between the wheel side member and the vehicle body side member; Roll angle calculation means for calculating a roll angle of a vehicle body based on the detection result of the damper stroke amount detection means, and the contact load calculation means calculates the distance based on the calculation result of the roll angle calculation means. Provided is a ground load estimation device characterized by correcting.

  Further, the invention according to claim 3 is provided on a wheel side member that moves up and down together with the wheel, and based on the detection result of the distance detection means and the distance detection means for detecting the distance to the road surface, the ground contact load of the wheel is determined. A ground load estimation device including a ground load calculation means for calculating a ground load estimation value, further comprising a steering angle detection means for detecting a steering angle of the steering, wherein the ground load calculation means is detected by the steering angle detection means. Provided is a ground load estimation device that corrects the distance based on a result.

  The invention according to claim 4 is provided on a wheel side member that moves up and down together with the wheel, and based on a detection result of the distance detection means and a distance detection means for detecting a distance to the road surface, the ground contact load of the wheel is determined. A ground load estimation device comprising a ground load calculation means for calculating a ground load estimation value, further comprising tire air pressure detection means for detecting tire air pressure, wherein the ground load calculation means is a detection result of the tire air pressure detection means. A ground load estimation device is provided which corrects the distance based on

  Further, the invention according to claim 5 is provided on a wheel side member that moves up and down together with the wheel, and based on the detection result of the distance detection means and the distance detection means for detecting the distance to the road surface, the ground contact load of the wheel is determined. In a ground load estimation device comprising a ground load calculation means for calculating as a ground load estimation value, the ground load estimation device further comprises a vehicle speed detection means for detecting a vehicle speed, wherein the ground load calculation means is based on a detection result of the vehicle speed detection means. Provided is a ground load estimation device characterized by correcting a distance.

  According to the present invention, the ground contact load of a wheel can be estimated from the deflection of a tire with sufficient accuracy to be used for vehicle motion control even in a vehicle motion state in which longitudinal acceleration and lateral acceleration are high or when traveling on an irregular road surface. The estimated ground contact load can be used for vehicle motion control that estimates the lateral force and longitudinal force of the tire. Specifically, by applying a lateral force that can be calculated from the calculated contact load and tire side slip angle to yaw moment control, slip angle control, and the like, it becomes possible to perform motion control with higher accuracy than before.

  Further, since the contact load can be calculated with high accuracy, the optimum damping force, displacement, etc. of the damper can be calculated from the calculated contact load. Furthermore, the ride quality can be improved by using this result for controlling the active damper, the actuator, and the like. Moreover, the control performance of roll motion and pitch motion can be further enhanced by using a highly accurate ground load result. Similarly, the optimum driving force and braking force of each tire can be calculated from the highly accurate contact load calculation result, and the optimal distribution of the driving force and braking force to each tire can be achieved. This makes it possible to perform motion control that makes the most of the driving force and braking force of the vehicle, such as improving acceleration performance and shortening the braking distance. Furthermore, the degree of wear of the tire can be determined using the result obtained by the present invention.

  Hereinafter, embodiments in which the present invention is applied to an automobile will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of an automobile according to the embodiment, FIG. 2 is a side view of a suspension of the automobile according to the embodiment, and FIG. 3 is a block diagram illustrating a schematic configuration of the ground load estimation device according to the embodiment. FIG. 4 is a flowchart of ground load estimation according to the embodiment. 5 is a graph showing the amount of tire displacement due to a change in camber angle, FIG. 6 is a graph showing the amount of tire displacement due to turning, FIG. 7 is a graph showing the load change due to turning, and FIG. FIG. 9 is a graph showing a tire diameter displacement amount due to a change in tire pressure, FIG. 9 is a graph showing a tire diameter displacement amount due to a change in vehicle speed, and FIG. 10 is a graph showing a load change due to a change in vehicle speed. FIG. 11 is a graph showing a spring constant according to a change in tire air pressure, and FIG. 12 is a graph showing a spring constant due to a change in vehicle speed. 5 to 7 and 10, f indicates a front wheel, r indicates a rear wheel, fr indicates a front right wheel, and fl indicates a front left wheel.

<< Configuration of Embodiment >>
<Automobile device configuration>
First, with reference to FIG. 1, the apparatus structure of the motor vehicle which concerns on embodiment is demonstrated. In the description, for the four wheels and members arranged for them, that is, the wheels and the attitude adjusting actuators, etc., the subscripts (fr, fl, rr, rl) indicating the front, rear, left, and right are described in the numerical symbols, respectively. )

  As shown in FIG. 1, an automobile 1 (vehicle) includes four wheels 4 including tires 2 and wheels 3, and each wheel 4 is rotatably supported by a knuckle 5 (wheel side member). . The wheel 4 and the knuckle 5 are suspended by a suspension 8. The automobile 1 includes an ECU (Electronic Control Unit) 9 and an EPS (Electric Power Steering) 10 which are main control units of the active suspension system. Further, the automobile 1 has a laser distance sensor 11 (distance detection means) that is attached to the knuckle 5 and measures the distance to the road surface, and a damper stroke sensor 12 (damper stroke amount detection means) that detects the stroke amount of the damper 7. In addition, a tire pressure sensor 13 (tire pressure detection means) installed on the wheel 3 for detecting the air pressure of the tire 2 is installed for each wheel 4, and a steering angle sensor 14 for detecting the steering angle of the steering ( Steering angle detection means) and a vehicle speed sensor 15 (vehicle speed detection means) for detecting the vehicle speed are installed.

  The ECU 9 includes a microcomputer, a ROM, a RAM, a peripheral circuit, an input / output interface, various drivers, and the like, and is connected to each of the sensors 11 to 15 via a communication line (CAN (Controller Area Network in this embodiment)). It is connected. Each sensor 11-15 outputs a detection result to ECU9, respectively. Although the tire pressure sensor 13 is shown as being connected to the ECU 9 for convenience in FIG. 1, the tire pressure sensor 13 actually transmits a detection result from the built-in antenna coil section, and is a pressure installed on the vehicle 1 body side. A measuring device (not shown) receives the detection result and outputs a signal to the ECU 9.

  The EPS 10 includes, as main components, a steering gear 21 including a rack and a pinion (not shown), a steering shaft 23 with a steering wheel 22 attached to the rear end, and an EPS motor 24 that applies a steering assist force to the steering shaft 23. A steering angle sensor 14 for detecting the steering angle of the steering wheel 22 is attached to the steering shaft 23.

<Suspension configuration>
Next, the suspension 8 will be described with reference to FIG. The suspension 8 includes the suspension arm 6, the damper 7, and the spring 16 as main components. The wheel 3 on which the tire 2 is mounted is rotatably supported by the knuckle 5 via a hub bearing (not shown). One end of the suspension arm 6 is connected to the lower side of the knuckle 5 via the support shaft 31, and the other end is connected to the vehicle body side member 33 via the support shaft 32. The lower end of the damper 7 is fixed and integrated with the upper part of the knuckle 5, and the upper end is connected to the vehicle body side member 33 via the bush 34. As described above, the knuckle 5 is suspended from the vehicle body side member 33 by the suspension 8 together with the wheels 4 and moves up and down together with the wheels 4. In the knuckle 5, a laser distance sensor 11 that detects a distance d to the road surface R is installed on the lower surface inside the wheel 3.

<Configuration of ground load estimation device>
As shown in FIG. 3, the ground load estimation device 40 mainly includes a laser distance sensor 11, a damper stroke sensor 12, a tire air pressure sensor 13, a steering angle sensor 14, a vehicle speed sensor 15, and a part of the ECU 9. As a component. The ECU 9 includes an input interface 41, a camber angle calculation unit 42, a roll angle calculation unit 43, a ground load calculation unit 44, and a ground load signal output unit. In addition to these, the ECU 9 includes a ROM, a RAM, a peripheral circuit, an input / output interface, various drivers, and the like. In the case of the present embodiment, the laser distance sensor 11, the damper stroke sensor 12, and the tire air pressure sensor 13 are installed for each wheel 4, and the ECU 9 estimates the ground load for each wheel 4.

  The detection result of the laser distance sensor 11 is input to the input interface 41 of the ECU 9 and is used for estimating the ground load in the ground load calculation unit 44. After the detection result of the damper stroke sensor 12 is input to the input interface 41, the camber angle calculation unit 42 and the roll angle calculation unit 43 are used to calculate the camber angle and the roll angle of the vehicle body, respectively. When calculating the roll angle, the difference between the left and right damper stroke amounts is used. In the contact load calculation unit 44, the camber angle calculation result is used for correction as a tire displacement amount due to a change in camber angle, and similarly, the roll angle calculation result is used as a tire displacement amount due to a change in roll angle. The detection result of the tire pressure sensor 13 is input to the input interface 41 and is used for correction by the ground load calculation unit 44 as a tire displacement amount due to a change in tire air pressure. Both detection results by the steering angle sensor 14 and the vehicle speed sensor 15 are also used for correction as a tire displacement amount due to steering and a tire displacement amount due to a change in vehicle speed, respectively. The estimated ground load signals Wfl, Wfr, Wrl, Wrr estimated by the ground load calculation unit 44 and output from the ground load signal output unit 45 are other parts in the ECU 9 that perform vehicle motion control, attitude control, and the like (FIG. (Not shown).

<< Operation of Embodiment >>
<Estimation of wheel contact load>
The present invention utilizes the fact that the ground contact load W of the wheel 4 is obtained from the following equation using the tire longitudinal spring constant k and the tire deflection ε.
Contact load W = (longitudinal spring constant k of tire) × (tire deflection ε)
As shown in FIG. 2, since the knuckle 5 moves up and down together with the wheels 4, the displacement of the tire 2 due to the ground load W can be detected as the displacement amount of the distance d to the road surface R output from the laser distance sensor 11. However, since the displacement amount of the distance d detected by the laser distance sensor 11 includes those due to various elements other than those due to the ground load W applied to the wheel 4, various corrections described later are performed. Then, the corrected displacement amount of the tire 2 is used as the tire deflection ε to estimate the ground load W applied to the wheel 4. By measuring the laser distance sensor 11 at a predetermined processing interval (for example, 10 ms), the displacement amount of the tire 2 can be continuously detected.

<Wheel contact load estimation procedure>
When the automobile 1 starts traveling, the ground load estimation device 40 performs estimation (calculation) of the wheel ground load shown in FIG. In the case of the present embodiment, the ECU 9 estimates the ground load W for each wheel 4, but since the procedure is the same, only the procedure for one wheel will be described in order to prevent the explanation from becoming complicated. However, since various behaviors differ for each wheel 4 with respect to various corrections, each will be described.

  As shown in FIG. 4, in step S1, detection results of various sensors 11 to 15 are read. Here, the tire displacement is calculated from the detection result (distance d) by the laser distance sensor 11. Next, in step S2, camber correction based on the damper stroke amount detection result is performed on the tire displacement amount calculated in step S1. Next, in step S3, roll correction based on the detection result of the damper stroke amount is performed on the tire displacement amount corrected in step S2. Next, in step S4, the steering angle correction is performed based on the steering angle detection result for the tire displacement amount that has been roll-corrected in step S3. Next, in step S5, tire pressure correction is performed based on the tire air pressure detection result with respect to the tire displacement amount that has been subjected to the steering angle correction in step S4. Next, in step S6, the vehicle speed correction is performed on the tire displacement amount corrected in the tire air pressure in step S5 based on the vehicle speed detection result. In step S7, a tire displacement amount (tire deflection ε) due to a load applied to the wheel 4 is calculated. Next, in step S8, the longitudinal spring constant k of the tire is calculated from the tire air pressure detection result and the vehicle speed detection result. Next, in step S9, the ground load W of the wheel 4 is estimated by multiplying the longitudinal spring constant k of the tire calculated in step S8 by the tire deflection ε calculated in step S7. This procedure is repeated at predetermined intervals. Hereinafter, various corrections will be described.

(Camber change correction)
The camber correction in step S2 is performed using the damper stroke amount detection result detected in step S1. Specifically, a relationship between the damper stroke amount and the tire displacement amount (distance d to be detected by the laser distance sensor 11) is obtained in advance by analysis using CATIA (registered trademark), and an approximation representing this relationship. Find the formula. In this embodiment, the analysis result by CATIA is as shown in FIG. The difference in the amount of tire displacement between the two when the damper stroke is large is due to the difference in suspension type. In this embodiment, the approximate expression representing these curves is
Tire displacement correction amount by camber yc (mm) = a + b × xc + c × xc ² + d × xc ³
Here, xc is expressed by a damper stroke amount. The coefficients a, b, c, and d are determined for the front and rear, respectively. Subsequently, the tire displacement correction amount yc by the camber is calculated using the damper stroke amount detection result from the above formula.

(Roll correction)
The roll correction in step S3 is performed using the damper stroke amount detection result detected in step S1, as in the camber correction. This corrects the amount of tire displacement due to the roll using the difference between the left and right damper stroke amounts. Specifically, first, the relation between the difference between the left and right damper stroke amounts obtained by actual running and the tire displacement amount is approximated. An approximate expression is created for each of the front and rear. In this embodiment, the approximate expression representing these curves is
Tire displacement correction amount by roll yr (mm) = e × (xrr−xrl)
Where xrr: right damper stroke amount
xrl: Expressed with the left damper stroke amount. The coefficient e is determined for each of the front and rear. Next, the tire displacement correction amount yr due to the roll is calculated using the damper stroke amount detection result detected from the above approximate expression.

(Rudder angle correction)
In the steering angle correction in step S4, the tire displacement amount due to the steering is obtained from the steering angle detection result detected in step S1. Specifically, first, the relationship between the change in the steering angle and the tire displacement is measured and calculated in advance, and an approximate expression of this relationship is obtained. In this embodiment, the relationship between the change in the steering angle and the amount of tire displacement is as shown in FIG. In this embodiment, the approximate expression representing these curves is
Tire displacement correction amount by turning ys (mm) = f + g × xs + h × xs ² + m × xs ³
Here, xs: Expressed by rudder angle. Note that the coefficients f, g, h, and m are determined for the front right and the front left, respectively. Next, the tire displacement correction amount ys by turning is calculated using the steering angle detection result from the above approximate expression.

  When measuring and calculating in advance the relationship between the change in steering angle and the amount of tire displacement, in order to eliminate the amount of tire displacement due to factors other than turning (that is, changes in load caused by turning), the following Perform the following process. First, the load applied to the wheel 4 when the rudder angle is changed is measured. Next, the tire displacement detected by the laser distance sensor 11 is calculated by dividing the difference between the load at the steering angle of 0 degrees and the load changed by the steering by the vertical spring constant of the tire to calculate the tire displacement amount by elements other than the steering. Subtract from the amount of displacement to find the amount of tire displacement due to turning. In the present embodiment, the relationship between the rudder angle and the load applied to the wheel 4 is as shown in FIG.

(Tire diameter displacement correction by changing tire pressure)
In the tire diameter displacement correction by the tire air pressure in step S5, the tire diameter displacement amount by the tire air pressure is obtained from the tire air pressure detection result detected in step S1. Specifically, first, the relationship between the tire pressure and the tire diameter displacement is measured in advance, and this approximate expression is obtained. In the present embodiment, the relationship between the tire air pressure and the tire diameter displacement amount is as shown in FIG. The prescribed air pressure of the tire is N, and the displacement amount from the tire diameter at that time is shown as the tire displacement amount. In this embodiment, the approximate expression representing this curve is
Correction amount of tire diameter displacement by tire pressure yp (mm) = n × (xp−N) + q × (xp−N) ²
Here, xp: tire air pressure N: represented by a specified tire air pressure. The coefficients n and q are determined for each front and rear (tire type / type). Next, a tire diameter displacement correction amount yp based on the tire air pressure is calculated using the tire air pressure detection result from the above approximate expression.

(Tire diameter displacement correction by changes in vehicle speed)
In the tire diameter displacement correction by the change in the vehicle speed in step S6, the tire diameter displacement amount by the change in the vehicle speed is obtained from the tire air pressure detection result detected in step S1. Specifically, first, the relationship between the vehicle speed and the tire diameter displacement is measured and calculated in advance, and this approximate expression is obtained. In this embodiment, the relationship between the change in vehicle speed and the tire diameter displacement is as shown in FIG. The approximate expression representing these curves in this embodiment is
Tire displacement correction amount yv (mm) due to changes in vehicle speed = r + s × xv + t × xv ²
Here, xv: Expressed by vehicle speed. Note that the coefficients r, s, and t are determined for each wheel 4. Next, a tire displacement correction amount yv due to a change in vehicle speed is calculated using the vehicle speed detection result from the above approximate expression.

  When measuring and calculating the relationship between the change in the vehicle speed and the tire diameter displacement amount in advance, in order to eliminate the tire displacement amount due to factors other than the vehicle speed (that is, the change in the load applied to the wheels 4), Perform proper processing. First, the load applied to the wheel 4 when the vehicle speed is changed is measured. Next, the tire displacement detected by the laser distance sensor 11 is calculated by dividing the difference between the load at a vehicle speed of 0 km / h and the load changed by increasing the vehicle speed by the longitudinal spring constant of the tire to calculate the tire displacement amount due to factors other than the vehicle speed Subtract from the amount of displacement to determine the amount of tire displacement due to changes in vehicle speed. In the present embodiment, the relationship between the vehicle speed and the load applied to the wheel 4 is as shown in FIG.

(Calculation of vertical spring constant of tire)
In step S8, the longitudinal spring constant k of the tire is calculated from the tire air pressure detection result and the vehicle speed detection result detected in step S1. Regarding the tire air pressure detection result, first, the relationship between the tire air pressure and the spring constant is measured, and an approximate expression thereof is obtained. In this embodiment, the relationship between the tire air pressure and the longitudinal spring constant of the tire is as shown in FIG. Note that the prescribed air pressure of the tire is N. As the tire pressure increases, the spring constant also increases. In this embodiment, the approximate expression representing these curves is
Longitudinal spring constant k (N / mm) due to tire pressure = u + v × xp + w × xp ²
Where xp: tire pressure. The coefficients u, v, and w are determined for the front and rear. Next, the longitudinal spring constant k based on the tire air pressure is calculated using the tire air pressure detection result from the above approximate expression.

Similarly, for the vehicle speed detection result, first, the relationship between the vehicle speed and the spring constant is measured by a single test, and an approximate expression thereof is obtained. In this embodiment, the relationship between the vehicle speed and the longitudinal spring constant of the tire is as shown in FIG. As the vehicle speed increases, the spring constant also increases. In this embodiment, the approximate expression representing these curves is
Longitudinal spring constant k (N / mm) according to vehicle speed = x + y × xv + z × xv ²
Here, xv: Expressed by vehicle speed. Note that the coefficients of x, y, and z are determined for the front and rear, respectively. Next, the longitudinal spring constant k according to the vehicle speed is calculated using the vehicle speed detection result from the above approximate expression. In calculating the tire longitudinal spring constant k, it is desirable to use a map representing the relationship between the longitudinal spring constant k and both elements of the tire air pressure detection result and the vehicle speed detection result.

  This is the end of the description of the specific embodiment, but the present invention is not limited to the embodiment shown here. For example, in the present embodiment, the contact load W of the wheel 4 is obtained from an approximate expression using the longitudinal spring constant k of the tire and the tire deflection ε, but the calculation expression is not limited to this, and the tire The contact load W may be obtained using a calculation formula, a map, or the like that incorporates the above characteristics. Similarly, when performing various corrections, the present embodiment calculates an approximate expression and calculates the tire displacement to be corrected. However, the calculation method is not limited to this, and a map or the like is used. The tire displacement amount may be obtained.

It is a schematic structure figure of a car concerning an embodiment. It is a side view of the suspension of the automobile concerning an embodiment. It is a block diagram which shows schematic structure of the ground load estimation apparatus which concerns on embodiment. It is a flowchart of grounding load estimation concerning an embodiment. It is a graph which shows the tire displacement amount by the change of a camber angle. It is a graph which shows the tire displacement amount by steering. It is a graph which shows the load change by turning. It is a graph which shows the tire diameter displacement amount by the change of a tire air pressure. It is a graph which shows the tire diameter displacement amount by the change of a vehicle speed. It is a graph which shows the load change by the change of a vehicle speed. It is a graph which shows the spring constant by the change of tire air pressure. It is a graph which shows the spring constant by the change of a vehicle speed.

Explanation of symbols

1 Car 2 Tire 3 Wheel 4 Wheel 5 Knuckle 6 Suspension Arm 7 Damper 8 Suspension 9 ECU
10 EPS
DESCRIPTION OF SYMBOLS 11 Laser distance sensor 12 Damper stroke sensor 13 Tire pressure sensor 14 Steering angle sensor 15 Vehicle speed sensor 33 Car body side member 40 Grounding load estimation apparatus 42 Camber each calculation part 43 Roll angle calculation part 44 Grounding load calculation part

Claims (5)

A distance detecting means that is installed on a wheel side member that moves up and down together with the wheel and detects a distance to the road surface;
In the ground load estimation device comprising the ground load calculation means for calculating the ground load of the wheel as a ground load estimated value based on the detection result of the distance detection means,
Damper stroke amount detecting means for detecting a stroke amount of a damper interposed between the wheel side member and the vehicle body side member;
A camber angle calculating means for calculating a camber angle based on the detection result of the damper stroke amount detecting means;
The ground load calculation unit corrects the distance based on a calculation result of the camber angle calculation unit. A distance detecting means that is installed on a wheel side member that moves up and down together with the wheel and detects a distance to the road surface;
In the ground load estimation device comprising the ground load calculation means for calculating the ground load of the wheel as a ground load estimated value based on the detection result of the distance detection means,
Damper stroke amount detecting means for detecting a stroke amount of a damper interposed between the wheel side member and the vehicle body side member;
Roll angle calculation means for calculating the roll angle of the vehicle body based on the detection result of the damper stroke amount detection means,
The ground contact load estimation device corrects the distance based on a calculation result of the roll angle calculation unit. A distance detecting means that is installed on a wheel side member that moves up and down together with the wheel and detects a distance to the road surface;
In the ground load estimation device comprising the ground load calculation means for calculating the ground load of the wheel as a ground load estimated value based on the detection result of the distance detection means,
A steering angle detecting means for detecting a steering angle of the steering;
The ground contact load estimating device corrects the distance based on a detection result of the steering angle detector. A distance detecting means that is installed on a wheel side member that moves up and down together with the wheel and detects a distance to the road surface;
In the ground load estimation device comprising the ground load calculation means for calculating the ground load of the wheel as a ground load estimated value based on the detection result of the distance detection means,
Tire pressure detecting means for detecting tire pressure is further provided,
The ground contact load calculation device corrects the distance based on a detection result of the tire air pressure detection device. A distance detecting means that is installed on a wheel side member that moves up and down together with the wheel and detects a distance to the road surface;
In the ground load estimation device comprising the ground load calculation means for calculating the ground load of the wheel as a ground load estimated value based on the detection result of the distance detection means,
It further comprises vehicle speed detection means for detecting the vehicle speed,
The ground load calculation device corrects the distance based on a detection result of the vehicle speed detection unit.

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