JP2015003686A - Vehicle stabilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent roll of a vehicle during traveling more surely.SOLUTION: A vehicle stabilizer 10 for suppressing roll of a vehicle controls vehicle travel by a predetermined control amount when lateral acceleration of the vehicle is equal to or more than a first predetermined value and steering angle speed is equal to or more than a second predetermined value. A first control threshold, a second control threshold, and the control amount are changed based on bias of each load applied to left and right wheels of the vehicle. Then the vehicle stabilizer 10 reduces the control threshold and increases the control amount as the bias of the load is larger.

Description

  The present invention relates to a vehicle stabilizer that prevents rolling of a running vehicle and stabilizes its posture.

  2. Description of the Related Art Conventionally, a vehicle stabilization device (side slip prevention device) that prevents rolling (rollover) of a running vehicle and stabilizes the posture is known. For example, in Patent Document 1 below, when the roll rate of the vehicle body is greater than or equal to a predetermined value, or when the steering angular velocity of the steering wheel is greater than or equal to a set angular velocity that can be rolled over regardless of the height of the center of gravity of the vehicle, A vehicle rollover prevention device is disclosed in which an apparatus is operated to accurately perform a rollover prediction at an early stage regardless of the height of the center of gravity of the vehicle, and an air brake device is appropriately operated.

Japanese Patent Laid-Open No. 11-011272

  In the technology according to the above-described conventional technology, the timing for starting control and the control amount (control strength) are determined mainly from the lateral acceleration and steering angular velocity of the vehicle. On the other hand, the ease of rollover of the vehicle is considered to be related to factors other than the lateral acceleration and the steering angular velocity, and there is a possibility that more stable traveling can be realized by taking these factors into consideration.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a vehicle stabilizer that can more reliably prevent a vehicle from rolling while traveling.

In order to solve the above-mentioned problems and achieve the object, a vehicle stabilizer according to the invention of claim 1 is a vehicle stabilizer that performs roll suppression control for suppressing rolls of a vehicle, and is arranged in the vehicle width direction of the vehicle. The lateral acceleration detecting means for detecting the lateral acceleration, the roll detecting means for detecting the roll rate of the vehicle, the steering angle detecting means for detecting the steering angle of the vehicle, and the steering detected by the steering angle detecting means. Steering angular velocity calculating means for calculating a steering angular velocity using an angle; Control means for controlling the traveling of the vehicle based on the lateral acceleration information and the steering angular velocity; and a vertical direction applied to the left wheel and the right wheel of the vehicle. Load estimating means for estimating each load, and the control means is configured to perform predetermined control when the lateral acceleration is equal to or greater than a first predetermined value and the steering angular velocity is equal to or greater than a second predetermined value. The travel of the vehicle is controlled by an amount, and the first predetermined value, the second predetermined value, and the control amount are changed based on bias of each load applied to the left wheel and the right wheel. And
According to a second aspect of the present invention, in the vehicle stabilizing device, the control means decreases the first predetermined value and the second predetermined value and increases the control amount as the load deviation increases. And
The vehicle stabilizer according to a third aspect of the invention is characterized in that the load estimating means estimates the load using a roll rate of the vehicle and vehicle specification information of the vehicle.
According to a fourth aspect of the present invention, in the vehicle stabilizing device, the load estimating means uses the roll acceleration obtained by differentiating the roll rate, the roll angle obtained by integrating the roll rate, and the vehicle specification information. It is characterized by estimating.
According to a fifth aspect of the present invention, there is provided the vehicle stabilizing device, wherein the control means controls the traveling of the vehicle by controlling a brake mechanism of each wheel of the vehicle and an engine output of the vehicle. .

According to the first aspect of the present invention, the control threshold value for estimating the vertical load applied to the left wheel and the right wheel of the vehicle and prescribing the timing to intervene in the control of each part of the vehicle based on the bias of each load applied to the left and right wheels. (Predetermined value) and control amount are changed. The ease with which a vehicle rolls over varies depending on the loading conditions of the vehicle and the slope of the road surface. By changing the control threshold and the control amount based on the load deviation of the left and right wheels, the roll of the vehicle can be more reliably suppressed.
According to the second aspect of the present invention, the predetermined value (control threshold value) is decreased and the control amount is increased as the load deviation between the left and right wheels is increased. As a result, when the load distribution on the left and right wheels is large, that is, when the load is tilted to either the left or right, it is easier to intervene by the vehicle stabilizer and more powerful control can be performed. It is possible to perform control according to the ease of roll.
According to the third and fourth aspects of the invention, since the load is estimated using the vehicle roll rate and the vehicle specification information, the cost can be kept low compared with the case where a load sensor is provided on the vehicle tire. be able to.
According to the invention of claim 5, since the brake mechanism of each wheel of the vehicle and the engine output of the vehicle are controlled, the behavior of the vehicle can be controlled and the vehicle posture can be stabilized.

1 is a block diagram showing a configuration of a vehicle stabilizer 10 according to an embodiment. It is explanatory drawing which shows the outline | summary of a control threshold value and control amount. 4 is a flowchart showing processing of the vehicle stabilization device 10.

  Exemplary embodiments of a vehicle stabilizer according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment)
FIG. 1 is a block diagram illustrating a configuration of a vehicle stabilizer 10 according to the embodiment. A vehicle stabilizer 10 according to an embodiment is a vehicle stabilizer that performs roll suppression control that suppresses roll of a vehicle, and includes a lateral acceleration sensor 102, a roll sensor 104, a handle angle sensor 106, a brake drive unit 112, and engine control. The unit 114 and the processing unit 200 are configured.

The lateral acceleration sensor 102 detects lateral acceleration applied in the vehicle width direction of a vehicle (hereinafter simply referred to as “vehicle”) on which the vehicle stabilizer 10 is mounted. That is, the lateral acceleration sensor 102 corresponds to the lateral acceleration detecting means in the claims.
The roll sensor 104 detects the roll rate (rolling angular velocity) of the vehicle, that is, the rotational angular velocity about the axis with the traveling direction of the vehicle as an axis. That is, the roll sensor 104 corresponds to the roll detection means in the claims.
The steering wheel angle sensor 106 is a rotation sensor provided on the steering wheel of the vehicle, and detects the steering angle of the vehicle. That is, the handle angle sensor 106 corresponds to the steering angle detection means in the claims.

The brake drive unit 112 drives a brake system provided on each wheel of the vehicle, and delays or stops the rotation of the wheel. In the present embodiment, the brake drive unit 112 operates by control of the processing unit 200 (travel control unit 212) in addition to the operation of a brake pedal (not shown) by the user.
The engine control unit 114 is, for example, an ECU (Engine Control Unit), and controls the engine output by comprehensively controlling an ignition mechanism, a fuel system, an intake / exhaust system, and the like of a vehicle engine. In the present embodiment, the vehicle is driven by the engine output. However, the present invention is not limited to this. For example, the vehicle may be an electric vehicle driven by a motor.

The processing unit 200 includes a CPU, a ROM that stores and stores a control program, a RAM as an operation area of the control program, an EEPROM that holds various data in a rewritable manner, an interface unit that interfaces with peripheral circuits, and the like. Composed.
When the CPU executes the control program, the processing unit 200 includes a steering angular velocity calculation unit 202, a vehicle specification information storage unit 204, a roll acceleration calculation unit 206, a roll angle calculation unit 208, a load estimation unit 209, parameter determination, and the like. Unit 210 and travel control unit 212 are realized.

  The steering angular velocity calculation unit 202 calculates the steering angular velocity using the steering angle detected by the steering wheel angle sensor 106 (steering angle detection means). The steering angular velocity is a speed at which the driver turns the steering wheel. The higher the steering angular velocity, the closer to the so-called steep steering wheel. The steering angular velocity calculation unit 202 corresponds to the steering angular velocity calculation unit in the claims.

The vehicle specification information storage unit 204 stores various types of information (vehicle specification information) indicating vehicle performance such as vehicle weight, roll radius (distance from the center of gravity of the vehicle to the roll center axis), dimensions, and the like. .
The roll acceleration calculation unit 206 differentiates the roll rate detected by the roll sensor 104 to calculate the roll acceleration (rolling angular acceleration) of the vehicle.
The roll angle calculation unit 208 integrates the roll rate detected by the roll sensor 104 and calculates the roll angle (rolling angle) of the vehicle.

The load estimation unit 209 estimates the vertical load applied to the left wheel and the right wheel of the vehicle. The load estimation unit 209 is calculated by the vehicle specification information and the roll acceleration stored in the vehicle specification information storage unit 204, more specifically, the roll acceleration and roll angle calculation unit 208 calculated by the roll acceleration calculation unit 206. From the roll angle, the respective loads of the left wheel (left front wheel + left rear wheel) and the right wheel (right front wheel + right rear wheel) of the vehicle are estimated. The sum of the loads on the left and right wheels is always constant, and it is considered that the vehicle is likely to roll when the load on either the left wheel or the right wheel is extremely small or large.
Instead of the load estimation unit 209, a load sensor that detects a load in the vertical direction may be provided on each wheel of the vehicle, and the state of the load applied to each wheel may be detected using the detection result.

The parameter determination unit 210 determines parameters such as a control threshold value and a control amount when the brake control unit 212 and the engine control unit 114 are controlled (roll suppression control) by the travel control unit 212 described later.
The control threshold value is a threshold value when the traveling control unit 212 starts the roll suppression control, and indicates the threshold values of the lateral acceleration and the steering angular velocity. That is, when the lateral acceleration is equal to or higher than the first predetermined value (first control threshold) and the steering angular velocity is equal to or higher than the second predetermined value (second control threshold), the travel control unit 212 performs roll suppression control. Start. Therefore, the roll suppression control is started while the lateral acceleration and the steering angular velocity are smaller as the control threshold is smaller.
Further, the control amount indicates the degree (intensity) that the traveling control unit 212 controls the brake drive unit 112 and the engine control unit 114, and indicates that stronger control is performed as the control amount is larger.

  FIG. 2 is an explanatory diagram showing an outline of the control threshold and the control amount, FIG. 2A shows the control threshold, and FIG. 2B shows the control value. 2A and 2B, the vertical axis represents the left wheel load, and the horizontal axis represents the right wheel load. The parameter determination unit 210 has a control threshold value and control amount table as shown in FIG. 2, and is based on the bias of each load applied to the left wheel and the right wheel of the vehicle estimated by the load estimation unit 209. A control threshold value of 1, a second control threshold value, and a control amount are determined. Although only one table is shown in FIG. 2A, actually, a first control threshold table indicating lateral acceleration and a second control threshold table indicating steering angular velocity are held. .

  The control threshold value shown in FIG. 2A is such that the value of the determined control threshold value becomes smaller as one of the left wheel load and the right wheel load is smaller and the other is larger, that is, the left and right loads are biased. For example, comparing point α and point β on FIG. 2A, the control threshold is lower at point β where the left wheel load is higher and the right wheel load is lower than point α where the left and right loads are substantially the same. Yes. That is, as the left and right loads are biased, the control threshold is set to a smaller value, and the roll suppression control is started while the lateral acceleration and the steering angular velocity are small.

  In the control amount shown in FIG. 2B, the value of the determined control threshold value becomes smaller as one of the left wheel load and the right wheel load is smaller and the other is larger, that is, the left and right loads are biased. For example, comparing point α and point β on FIG. 2B, the amount of control is greater at point β where the left wheel load is higher and the right wheel load is lower than point α where the left and right loads are substantially the same. Yes. That is, as the load on the right and left sides is biased, the control amount is set to a larger value, and the brake drive unit 112 and the engine control unit 114 are more strongly controlled.

In other words, the parameter determination unit 210 decreases the first control threshold and the second control threshold and increases the control amount as the load deviation between the left and right wheels increases.
The values and graphs of the control threshold value and the control amount in FIG. 2 are schematically shown to show the magnitude relationship between the control threshold value and the control amount determined by the bias of the left and right wheel loads. Is different.

  Returning to the description of FIG. 1, when the lateral acceleration is equal to or higher than the first predetermined value (first control threshold) and the steering angular velocity is equal to or higher than the second predetermined value (second control threshold), The vehicle travel is controlled by a predetermined control amount. As described above, the predetermined value (control threshold value) and the control amount are changed by the parameter determination unit 210 based on the load distribution of the left and right wheels. That is, the parameter determination unit 210 and the travel control unit 212 correspond to the control unit in the claims.

  The travel control unit 212 controls the brake drive unit 112 and the engine control unit 114 according to the control amount determined by the parameter determination unit 210, and adjusts the braking and engine output of each vehicle wheel. That is, the traveling control unit 212 controls the traveling of the vehicle by controlling the brake mechanism of each wheel of the vehicle and the engine output of the vehicle.

FIG. 3 is a flowchart showing the processing of the vehicle stabilizer 10. While the vehicle is running, the vehicle stabilizer 10 continues to perform the processing shown in FIG.
In the flowchart of FIG. 3, the vehicle stabilizer 10 first detects the roll rate, steering angle, and lateral acceleration of the vehicle using the roll sensor 104, the handle angle sensor 106, and the lateral acceleration sensor 102 (step S301).

  Next, the vehicle stabilizer 10 calculates the steering angular velocity using the steering angle by the steering angular velocity calculation unit 202 (step S302). Further, roll acceleration and roll angle are calculated by roll acceleration calculation unit 206 and roll angle calculation unit 208 (step S303). Further, the load estimation unit 209 estimates the loads on the left and right wheels of the vehicle using the roll acceleration and roll angle calculated in step S303 and the vehicle specification information (step S304).

  The vehicle stabilizer 10 determines whether or not the load on the left and right wheels has changed by the parameter determination unit 210 (step S305). When the load changes (step S305: Yes), the first control threshold value, the second control threshold value, and the control amount are changed with reference to a table as shown in FIG. 2 (step S306). On the other hand, when there is no change in the load (step S305: No), the currently set control threshold and control amount are continued.

  The travel control unit 212 determines whether or not the lateral acceleration detected in step S301 is equal to or greater than the first control threshold value set (or continuously set) in step S306, and the steering angular velocity calculated in step S302. Is greater than or equal to the second control threshold (step S307). When the lateral acceleration is equal to or higher than the first control threshold and the steering angular velocity is equal to or higher than the second control threshold (step S307: Yes), the brake is driven with the control amount set (or set continuously) in step S306. Control unit 112 (brake) and engine control unit 114 (engine) are controlled (step S308). On the other hand, when the lateral acceleration is less than the first control threshold or the steering angular velocity is less than the second control threshold (step S307: No), the processing from step S301 is repeated without performing the control.

  As described above, the vehicle stabilizer 10 according to the embodiment estimates the load in the vertical direction applied to the left wheel and the right wheel of the vehicle, and controls each part of the vehicle based on the bias of the loads applied to the left and right wheels. The control threshold value (predetermined value) and control amount that define the intervention timing are changed. The ease with which a vehicle rolls over varies depending on the loading conditions of the vehicle and the slope of the road surface. By changing the control threshold and the control amount based on the load deviation of the left and right wheels, the roll of the vehicle can be more reliably suppressed.

  In addition, the vehicle stabilizer 10 decreases the predetermined value (control threshold) and increases the control amount as the load deviation between the left and right wheels increases. As a result, when the load distribution on the left and right wheels is large, that is, when the load is tilted to either the left or right, it is easier to intervene by the vehicle stabilizer and more powerful control can be performed. It is possible to perform control according to the ease of roll.

  Further, since the vehicle stabilizer 10 estimates the load using the vehicle roll rate and the vehicle specification information of the vehicle, the cost can be reduced compared to the case where a load sensor is provided on the vehicle tire.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle stabilizer, 102 ... Lateral acceleration sensor, 104 ... Roll sensor, 106 ... Steering angle sensor, 112 ... Brake drive part, 114 ... Engine control part, 200 ... Processing part, 202 ... Steering angular velocity calculation unit, 204 ... vehicle specification information storage unit, 206 ... roll acceleration calculation unit, 208 ... roll angle calculation unit, 209 ... load estimation unit, 210 ... parameter determination unit, 212 ... travel control Department.

Claims (5)

A vehicle stabilizer that performs roll restraint control to restrain a roll of a vehicle,
Lateral acceleration detection means for detecting lateral acceleration in the vehicle width direction of the vehicle;
Roll detecting means for detecting the roll rate of the vehicle;
Steering angle detection means for detecting the steering angle of the vehicle;
Steering angular velocity calculation means for calculating a steering angular velocity using the steering angle detected by the steering angle detection means;
Control means for controlling travel of the vehicle based on the lateral acceleration information and the steering angular velocity;
Load estimating means for estimating the load in the vertical direction applied to the left wheel and the right wheel of the vehicle, respectively,
The control means controls the traveling of the vehicle by a predetermined control amount when the lateral acceleration is equal to or higher than a first predetermined value and the steering angular velocity is equal to or higher than a second predetermined value, and the first predetermined value, Changing the second predetermined value and the control amount based on a bias of each load applied to the left wheel and the right wheel;
A vehicle stabilizer characterized by that. The control means decreases the first predetermined value and the second predetermined value and increases the control amount as the load bias is larger.
The vehicle stabilizer according to claim 1. The load estimating means estimates the load using a roll rate of the vehicle and vehicle specification information of the vehicle;
The vehicle stabilizer according to claim 1 or 2, wherein the vehicle stabilizer is provided. The load estimating means estimates the load using a roll acceleration obtained by differentiating the roll rate, a roll angle obtained by integrating the roll rate, and the vehicle specification information.
The vehicle stabilizer according to claim 3. The control means controls traveling of the vehicle by controlling a brake mechanism of each wheel of the vehicle and an engine output of the vehicle.
The vehicle stabilizer according to any one of claims 1 to 4, wherein the vehicle stabilizer is provided.

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