KR101894844B1 - Rough Road Detection System based on the Steering Torque of Vehicle - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a technique for detecting in real time whether a road surface on which a vehicle is currently traveling is detected in real time, and more particularly to a technique for detecting a torque applied to a steering shaft using a torque sensor mounted on a steering column And a technology for detecting whether or not the road surface is currently running. In addition, the present invention relates to a technique for using individual hull information to convert individual chassis control systems into a mode suitable for rough roads in rough roads.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a steering torque-

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a technique for detecting in real time whether a road surface on which a vehicle is currently traveling is detected in real time, and more particularly to a technique for detecting a torque applied to a steering shaft using a torque sensor mounted on a steering column And a technology for detecting whether or not the road surface is currently running. In addition, the present invention relates to a technique for using individual hull information to convert individual chassis control systems into a mode suitable for rough roads in rough roads.

Generally, when the vehicle travels on a rough road, a negative phenomenon occurs in the performance of the vehicle, such as a kickback phenomenon, a rickety feeling, a possibility of a failure due to an impact, and the like. Therefore, it is necessary to apply the functions corresponding to the obstacle. For this purpose, it is essential to detect the road surface roughness in real time.

Conventional rough detection methods are driven system based detection methods such as using a wheel speed sensor or a transmission output speed estimated by a TCU (Transmission Control Unit).

That is, a wheel speed gradient is calculated from a wheel speed signal obtained from an ABS / TCS / ESP or an additional wheel speed sensor of the vehicle, and the vehicle speed change rate corresponding to the calculated wheel speed gradient is set to a predetermined threshold value It is determined to be a rough road.

However, in the conventional vehicle system, even if the vehicle is running on a general road other than the rough road, if the vehicle speed of the vehicle suddenly changes including a low-speed section such as when the vehicle starts or stops, Diagnostic logic frequently diagnoses this as a rough run. In this way, if the vehicle system is diagnosed as a rough road, it is possible to cause false diagnosis because the fault diagnosis fades out as a result of the fault diagnosis.

In addition, the above-described wheel-based detection method is likely to cause malfunction due to factors such as the air pressure of the tire, and the transmission output speed based detection method is disadvantageous in that it can be detected only on rough roads where road surface changes are severe.

Also, considering the case where the detected obstacle information is used for the function related to the steering system, there is a disadvantage that it is difficult to consider the influence on the steering system since the indirect information derived from the driveline system must be used.

The present invention has been made to solve the above problems,

The present invention relates to a technique for measuring a torque applied to a steering shaft by using a torque sensor mounted on a steering column of a vehicle and detecting a road roughness of a road on which the vehicle is traveling based on the measured torque. It is also an object of the present invention to provide a steering torque based fault detection system for a vehicle in which individual chassis control systems are automatically converted to a mode suitable for rough roads by using the detected obstacle information.

According to an aspect of the present invention,

A steep road detection system for a vehicle, comprising: a steering torque sensor signal processing unit for receiving an output of a steering torque sensor of a vehicle and measuring a steering torque; A steering torque change rate calculation unit for calculating a rate of change per unit time of the steering torque measured by the steering torque sensor signal processing unit; An obstacle determination reference value calculation unit for interpolating a map of the vehicle speed to determine an obstacle determination reference value for the current vehicle speed; An obstacle judgment flag determining unit for comparing the rate of change of the steering torque with the obstacle judgment reference value and outputting an obstacle judgment flag; And a final obstacle flag determining unit for determining an obstacle traveling based on the obstacle judging criteria Flag; And a control unit.

The apparatus of claim 1, further comprising: an obstacle entry determination unit that incorporates an ON timer and measures the number of times the obstacle determination flag becomes ON (or 1) during the operation time of the ON timer, wherein the final obstacle flag determination unit When the number of times that the obstacle judgment flag is ON (or 1) measured by the entrance judging unit exceeds a preset reference value, it is regarded that the obstacle has entered the obstacle.

An obstacle escape judging unit including an OFF timer and resetting the OFF timer when the obstacle judgment flag becomes ON (or 1); Wherein the final obstacle flag determination unit is configured to regard the obstacle as an escape when the OFF timer is increased beyond a predetermined time.

The steering torque change rate calculator calculates the absolute value of the change rate per unit time of the steering torque measured by the steering torque sensor signal processor.

The present invention as described above provides the following effects.

- Performance improvements

In the case of the conventional obstacle detection method, since the drift system based on the vehicle's wheel speed or transmission output speed is used, a case of misdiagnosis may occur. However, since the present invention is a steering system based method, Even if it is difficult to detect the obstacle. Therefore, it is possible to improve the performance of the fail / safe control of the vehicle. Further, as described above, since the present invention is a steerometer-based roughness detection technique, there is an effect that the roughness can be detected in consideration of the direct influence on the steering system.

- Improved merchandising

It is possible to directly consider the influence of the kickback phenomenon that may occur as the vehicle travels along the rough road, thereby improving the steering feeling that the driver feels.

1 is a block diagram showing a steering torque-based roughness detection system for a vehicle according to a preferred embodiment of the present invention.

The steering torque-based roughness detection system of a vehicle according to the present invention measures a torque applied to the steering shaft by using a torque sensor mounted on a steering column of a vehicle, and determines whether or not the current running road is rough . Also, by using the obstacle information recognized through the torque sensor, the individual chassis control systems can be automatically converted into a mode suitable for rough roads in the rough road, so that the steering can be easily performed on the rough roads and the ride comfort lowering phenomenon is reduced.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

1 is a block diagram showing a steering torque-based roughness detection system for a vehicle according to a preferred embodiment of the present invention.

As shown in the figure, the steering torque based obstacle detection system of the present invention includes a steering torque sensor signal processing unit 10, a steering torque change rate calculation unit 20, a roughness determination reference value calculation unit 30, (40), an obstacle entry determination unit (50), an obstacle exit determination unit (60), and a final obstacle flag determination unit (70).

The steering torque sensor signal processing unit 10 is a module that receives a steering torque output from a torque sensor mounted on a steering shaft of a vehicle and measures the steering torque of the vehicle. At this time, the steering torque sensor signal processing unit 10 receives an analog output generated from the steering torque sensor and performs A / D conversion to obtain a steering torque usable in a steering torque based fault detection system of the present invention And measures it.

The steering torque signal output from the chassis CAN of the MDPS system may be used in place of the steering torque sensor signal processing unit 10 in another embodiment of the present invention. Generally, when the vehicle is equipped with the MDPS system, the steering torque signal is output through the chassis CAN, so that the steering torque sensor signal processing unit 10 can be replaced with the corresponding signal.

The steering torque change rate calculation unit 20 calculates a rate of change of the steering torque measured by the steering torque sensor signal processing unit 10 and calculates a rate of change of the steering torque by performing a differential with respect to the steering torque measured per unit time .

Preferably, the steering torque change rate calculation section 20 calculates the rate of change by differentiating the steering torque received from the steering torque sensor signal processing section 10 per unit time, calculates the rate of change by taking the absolute value of the calculated differential value do. At this time, the calculation formula is as follows.

* Output value: | d (StrTq) / dt | (StrTq = steering torque, t = time)

The obstacle determination reference value calculation unit 30 is a module for calculating a reference value for determining an obstacle according to the state of a road on which the vehicle is moving. The obstacle determination reference value calculation unit 30 interpolates a map (x: vehicle speed, y: And determines the roughness judgment reference value for the current vehicle speed.

At this time, the map is determined on the basis of the data calculated through the actual vehicle test of the vehicle in advance. The determination of road surface roughness for the actual vehicle test can be made based on the amplitude magnitude in the frequency range in which the human body can be detected in the power spectrum analysis of the vehicle vertical acceleration data.

The steepness reference value calculation unit 30 measures the steering torque during running at a constant vehicle speed on the roads to be judged to be rough roads and roads to be judged to be rough roads and then analyzes the distribution of the absolute values of the change rates of the steering torque, The median value is determined as the threshold value of the obstacle judgment at the corresponding vehicle speed.

Therefore, by comparing the rough road reference value calculated by the rough road reference value calculator 30 and the steering torque change ratio calculated by the steering torque change rate calculator 20, it is judged whether or not the state of the road in which the vehicle is running is rough .

The steepness criterion flag determination unit 40 compares the absolute value of the steering torque change ratio calculated by the steepness torque change ratio calculation unit with the reference value calculated by the steepness criterion value calculation unit 30 to determine the roughness And generates a determination criterion Flag.

The steepness criterion flag determiner 40 compares the absolute value of the steer-torque change rate with a reference value and outputs different steepness criterion flags when the absolute value of the steer- ing torque change rate becomes larger or smaller than the reference value, It indicates whether the road in which the vehicle is traveling is rough or not.

For example, when the absolute value of the steering torque change rate becomes greater than the reference value, the roughness determination flag determination unit 40 outputs the roughness determination flag as On (or 1) Or 0). For example, if it is continuously small, large, or small, Off (or 0) is output.

The steepness criterion flag determiner 40 compares the absolute value of the steer-torque change rate with the reference value continuously during the vehicle running to generate and output a steepness criterion Flag.

The rough road entry determination unit 50 is a module for determining whether or not a vehicle under running enters a rough road using the rough road flag Flag output from the rough road flag determination unit 40.

The obstacle entry determination unit 50 includes an ON timer and operates the ON timer when the obstacle determination flag is ON (or 1) from the obstacle determination flag determination unit 40 . The ON timer is a timer operated for a predetermined unit time, and is provided for counting the number of times the abnormality determination flag is outputted as On (or 1) per unit time.

Therefore, the obstacle entry determination unit 50 counts the number of times the obstacle judgment flag becomes On (or 1) while the ON timer is operating. At this time, when the number of times that the predetermined number of counts is set and the obstacle judgment flag becomes On (or 1) while the ON timer is operating is equal to or more than a preset count number , The vehicle is considered to have entered the rough road.

The obstacle avoidance determination unit 60 determines whether the vehicle entering the obstacle has escaped from the obstacle by using the obstacle judgment flag Flag output from the obstacle judgment standard Flag determination unit 40. [

The obstacle avoidance determination unit 60 includes an OFF timer which is operated for a predetermined unit time. The OFF timer is operated for a preset unit time, and is reset to 0 every time when the roughness judgment reference flag is outputted from the roughness judgment reference flag judgment unit 40 as On (or 1).

Therefore, when the OFF timer increases for a predetermined time or more, it can be regarded that the obstacle judgment flag is not output for a predetermined time (or 1), and therefore, the obstacle is considered to have escaped.

The final obstacle flag determination unit 70 generates a final obstacle flag by synthesizing whether or not the obstacle entry / exit determination is made by the obstacle entry determination unit 50 and the obstacle exit determination unit 60.

The final obstacle flag determination unit 70 outputs On (or 1) when the vehicle runs on rough roads, and Off (or 0) when the road is not rough. Therefore, whether or not the vehicle enters an obstacle can be determined through the output value output from the final obstacle flag determination unit 70.

The steering torque-based roughness detection system of the vehicle as described above can determine the rough running using the steering torque, so that it is possible to control the running mode of the vehicle according to the roughness recognized during the running of the vehicle.

For example, the information of the road surface detected based on the steering torque can be applied to the known intelligent traveling mode integrated control (i-DMIC) technology.

The intelligent traveling mode integrated control includes an automatic mode for automatically grasping the state of the vehicle or the road surface and automatically optimizing the traveling mode of the individual chassis system. Therefore, the vehicle to which the steering torque-based roughness detection system according to the present invention is applied recognizes the state of the road under driving and uses the final final road flag so that the steering kickback phenomenon and the ride comfort deterioration The driving mode of the individual chassis system can be changed as shown in Table 1 below.

Individual chassis system engine T / M MDPS CDC ESC
Runway mode Normal No Change Comport Normal Normal

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. no. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

10: Steering torque sensor signal processor
20: Steering torque change rate calculation unit
30: roughness judgment reference value calculation section
40: Judgment Criteria of Flag
50: Judgment as to whether or not to enter the obstacle
60: Judgment as to whether or not the escape route is escaped
70: final obstacle flag judgment unit

Claims (4)

In an obstacle detection system for a vehicle,
A steering torque sensor signal processing unit for receiving the output of the steering torque sensor of the vehicle and measuring the steering torque;
A steering torque change rate calculation unit for calculating a rate of change per unit time of the steering torque measured by the steering torque sensor signal processing unit;
An obstacle determination reference value calculation unit for interpolating a map of a vehicle speed to analyze a distribution of absolute values of a change rate of the steering torque with respect to a current vehicle speed and determining an intermediate value thereof as an obstacle determination reference value in the vehicle speed;
An obstacle judgment flag determining unit for comparing the rate of change of the steering torque with the obstacle judgment reference value and outputting an obstacle judgment flag; And
And a final obstacle flag judging section for judging an obstacle road run through an obstacle judging standard Flag,
Further comprising an obstacle entry determination unit that incorporates an ON timer and measures the number of times the obstacle determination flag becomes ON (or 1) during the operation time of the ON timer,
The final error flag determination unit may determine,
Wherein when the number of times the obstacle judging flag judged by the obstacle judging flag is ON (or 1) exceeds a preset reference value, it is judged that the obstacle has entered the obstacle.
delete The method according to claim 1,
OFF timer, and the OFF timer is reset when the obstacle judgment flag becomes ON (or 1); Further comprising:
The final error flag determination unit may determine,
And when the OFF timer is increased beyond a predetermined time, it is regarded that the obstacle has escaped.
The method according to claim 1,
The steering torque change rate calculation unit may calculate,
Wherein the absolute value of the change rate per unit time of the steering torque measured by the steering torque sensor signal processing section is calculated.

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