KR20000032365A - Separative perceiving method of turning and tire abnormality - Google Patents

Abstract

PURPOSE: A separative perceiving method of turning and tire abnormity is provided to prevent misperception of a tire abnormity due to turning driving by separating a turning driving and an air pressure diminishment without additive mount of a special hardware. CONSTITUTION: A separative perceiving method of turning and tire abnormity comprises a wheel speed perceiving step, a differential value calculating step for calculating the differential values of wheels perceived, a differential mean value calculating step for calculating the mean values of the differential values, a turning determination step for determining if the vehicle is turning or not according to the respective differential mean values of the wheels and the wheel speeds, a tire abnormity determining step for determining if the tire is normal or not through a turning time of the vehicle when the vehicle is turning, an alarming step for alarming when the tire is abnormal, wherein without adding of a special hardware, the turning and the abnormity of tire of the vehicle is perceived.

Description

How to detect turning and tire troubles

Vehicles are equipped with a brake system for braking. Recently, various kinds of systems have been proposed for obtaining a stronger and more stable braking force. Among them, the anti-lock brake system is the most progressive.

The anti-lock brake system is equipped with a drum or caliper hydraulic brake device that generates braking force by hydraulic pressure on the front wheel and the rear wheel, respectively. consist of.

The power booster is a device that generates a large braking force with a small force by using a pressure difference between the vacuum and the atmosphere. The master cylinder receives the amplified force from the booster to form the braking hydraulic pressure. The master cylinder is connected to each brake system through a hydraulic line.

Solenoid valves are provided on the inlet and outlet sides of each brake device to control the hydraulic pressure delivered to each brake device. This is divided into a normal-open solenoid valve disposed at the inlet side and a normal-closed solenoid valve disposed at the outlet side, and is controlled by the ECU to exhibit a strong and stable braking force. At this time, the ECU detects the vehicle speed through the wheel sensors provided on the front wheel and the rear wheel to control them.

In addition, low pressure accumulators are installed downstream of the normal-closed solenoid valves on the front and rear wheels to temporarily store oil discharged from the brake in the decompression mode. In addition, a high pressure accumulator is installed at the rear of the low pressure accumulator, and a pump driven by a motor is formed therebetween to pressurize the low pressure oil stored in the low pressure accumulator to pump the high pressure accumulator. .

If the driver presses the brake pedal while the vehicle with the anti-lock brake system configured as described above is driving, braking hydraulic pressure is generated in the master cylinder. This braking hydraulic pressure is transmitted to the respective brake devices provided on the front wheels and the rear wheels through a normal open solenoid valve to perform a braking action.

On the other hand, when excessive braking pressure is transmitted than the road condition, the tire of the vehicle stops rotating and slips, and a kind of slip phenomenon occurs. To pass. Accordingly, the ECU lowers the braking pressure by operating the normally closed solenoid valve to open, thereby removing oil in the brake device. The oil discharged through the normal closed solenoid valve is moved to the first and second low pressure accumulators and stored for a while. As the motor is driven, the first and second high pressure accumulators and the master cylinder or the normal open solenoid valve are operated. Will cycle back to.

As a result, when the vehicle is braked, the anti-lock brake system control prevents the wheels from locking because the tires are grounded in the most ideal state.In the road conditions where the four wheels are rotated differently in rain or snow, and the road conditions are poor. This prevents slipping and loss of direction.

However, such an anti-lock brake system may cause a malfunction if the air pressure of the vehicle is not maintained at an optimum state. In other words, when one of the wheel tires is driven in a state where the air pressure is reduced, a difference in rotational speed is generated even in normal driving, and a detection signal is input to the ECU through the wheel sensor, thereby causing ABS malfunction. In addition, there is a problem in that the safety of the tire due to the deterioration of the air pressure, resulting in economic losses due to the increase in fuel economy.

Therefore, in order to detect the air pressure of a tire, conventionally, a standard deviation of an average vehicle speed of four wheels is detected, and a tire radius according to the vehicle speed is estimated and detected.

In addition, when the tire is replaced, the reset switch is artificially operated to recognize whether the tire is replaced or not, so that the pneumatic pressure detection due to the tire replacement is prevented. There was a problem that the alarm is determined by determining the change in air pressure according to the tire.

The present invention is to solve the above problems, an object of the present invention is to turn and tire abnormality to detect the turning and tire tire pressure abnormality according to the differential speed of the wheel speed and the wheel speed without additional hardware It is to provide a classification detection method.

1 is a schematic block diagram of a tire abnormality detection apparatus according to the present invention.

2 is a main flowchart of a turning and tire abnormality detection method according to the present invention.

3 is a turning driving judgment subroutine of the turning and tire abnormality detection method according to the present invention of FIG.

4 is a tire abnormality detection subroutine of the turning and tire abnormality detection method according to the present invention of FIG.

Explanation of symbols on the main parts of the drawings

10: wheel sensor 11: brake pedal

12: brake pedal detection unit 20: control unit

31: alarm drive 32: lamp

33: Speaker

The present invention for achieving the above object, the wheel speed detection step of detecting the wheel speed, the differential value calculation step of calculating the derivative value of the wheel speed detected in the wheel speed detection step, and the derivative calculated in the derivative value calculation step A tire abnormality detection method comprising a step of calculating a differential mean value for calculating an average value of values, wherein the vehicle is driven according to an average value of the wheel speed of each wheel detected in the wheel speed detection step and the derivative of each wheel calculated in the step of calculating the differential mean value. In the turning judgment stage to judge the turning, if the vehicle turns in the turning judgment stage, it detects the turning time of the vehicle and judges whether the tire is abnormal. It is a method characterized in that it comprises an alarm step.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment.

1 is a schematic block diagram of a tire abnormality detection apparatus according to the present invention.

2 is a main flowchart of a turning and tire abnormality detection method according to the present invention.

3 is a turning driving judgment subroutine of the turning and tire abnormality detection method according to the present invention of FIG.

4 is a tire abnormality detection subroutine of the turning and tire abnormality detection method according to the present invention of FIG.

Referring to the configuration according to the present invention with reference to Figure 1, first, the wheel sensor 10 for detecting the wheel speed of each wheel is connected to the control unit 20. And the brake pedal detection part 22 which detects operation of the brake pedal 21, and outputs the signal is electrically connected to the control part 20. As shown in FIG. In addition, under the control of the controller 20, an alarm driver 31 for visually and audibly alerting through the lamp 32 and the speaker 33 is connected to the controller 20.

Meanwhile, the above-described control unit 20 may be implemented as an ECU of an antilock brake system or a brake traction control system.

Turning to Figures 2, 3, 4 will be described the turning and tire abnormality detection method according to the present invention.

The controller 20 receives a signal from the wheel sensor 10 of each wheel and calculates a differential value between the wheel speed and the wheel speed (S110). The time it takes to calculate the wheel speed and derivative is about 7 ms.

After calculating the differential value of the wheel speed and the wheel speed, the control unit 20 determines whether the first reference time has elapsed in order to calculate the differential average value (S120). At this time, the first reference time is about 1 second, and it is determined whether the first reference time has elapsed in order to calculate an average of the derivative value of the wheel speed during that 1 second.

If it is determined in S120 that the first reference time has elapsed, the controller 20 calculates a derivative average value of wheel speeds of the respective wheels (S130).

After calculating the differential mean value, the controller 20 determines whether the second reference time has elapsed to calculate the deviation value of each wheel (S140). At this time, the second reference time is about 10 seconds, and it is determined whether the second reference time has elapsed in order to calculate the deviation value of the wheel speed of each wheel during the 10 seconds, and the longer the second reference time is, the more accurate the deviation value is. Can be calculated, but the time is set to 10 seconds considering data processing. The second reference time may be set to 10 seconds or more as described above.

If it is determined in S140 that the second reference time has elapsed, the controller 20 calculates wheel speed deviation of each wheel (S150).

If it is determined in the determination S120 that the first reference time has not elapsed or if it is determined in the determination S140 that the second reference time has not elapsed or the wheel speed deviation is calculated, the controller 20 turns the vehicle and the tire. In order to determine the air pressure abnormality, the turning and tire abnormality detection subroutine S200 is executed.

First, the control unit 20 determines that the wheel speed of the right wheel FR of the front wheel is faster than the wheel speed of the left wheel of the front wheel, and the wheel speed of the right wheel RR of the rear wheel is faster than the wheel speed of the left wheel RL of the rear wheel. It is determined whether the fast (S201).

In the determination S201, the wheel speed of the right wheel FR of the front wheel is faster than the wheel speed of the left wheel of the front wheel, and the wheel speed of the right wheel RR of the rear wheel is faster than the wheel speed of the left wheel RL of the rear wheel. When the controller 20 determines whether the average differential value kph of the wheel speeds of the right front and rear wheels FR and RR is greater than or equal to the reference value (S202). The reference value is about 1 kph.

If it is determined in S202 that the average differential values of the wheel speeds of the right front and rear wheels FR and RR are all equal to or greater than the reference value, the control unit 20 determines that the right turn is made based on the value of the priority counter that counts the time first. After setting the counter value, a turning flag indicating turning of the vehicle is set (S203). At this time, the reference counter value set in the priority counter is the reference time for determining that the vehicle is not turning when the average speed value of the wheel speeds of the front and rear wheels (FR, RR) is lower than the reference value. Will be described later.

After setting the turning flag, the right tire abnormality counter is increased (S205). Then, it is determined whether the right tire abnormality counter value is greater than or equal to the reference value (S206). If it is determined in step S206 that the right tire abnormality counter value is not equal to or greater than the reference value, the controller 20 resets the tire abnormality flag (S211) and returns to the main routine.

On the other hand, if it is determined in step S202 that the wheel speed differentials of the right front and rear wheels FR and RR are not equal to or greater than the reference value, the controller 20 decreases the value of the priority counter set as the reference counter value in the previous step. (S208). The control unit 20 determines whether the value of the priority counter is zero after reducing the value of the priority counter (S209).

If it is determined in step S209 that the value of the priority counter is zero, the controller 20 resets the turning flag (S210) and resets the tire abnormality detection flag (S211).

However, if it is determined in S209 that the value of the priority counter is not zero, the controller 20 sets the turning flag S204, and maintains the state if the turning flag is set. And the right tire over the counter to increase (S205).

After increasing the right tire abnormality counter, it is determined whether the value of the right tire abnormality counter is equal to or greater than the reference value (S206).

If it is determined in the determination S206 that the right tire abnormality counter value is equal to or greater than the reference value, the tire abnormality flag is set (S211).

On the other hand, in the determination S201, the wheel speed of the right wheel FR of the front wheel is not faster than the wheel speed of the left wheel of the front wheel, or the wheel speed of the right wheel RR of the rear wheel is faster than the wheel speed of the left wheel RL of the rear wheel. If it is determined that it is not fast, the control unit 20 determines that the wheel speed of the left wheel FL of the front wheel is faster than the wheel speed of the right wheel FR of the front wheel, and the wheel speed of the left wheel RL of the rear wheel is the right wheel of the rear wheel ( It is determined whether it is faster than the wheel speed of RR) (S220).

In the determination S220, the wheel speed of the left wheel FL of the front wheel is faster than the wheel speed of the right wheel of the front wheel, and the wheel speed of the left wheel RL of the rear wheel is faster than the wheel speed of the right wheel RR of the rear wheel. When the control unit 20 determines whether the average differential value kph of the wheel speeds of the left front and rear wheels FL and RL is greater than or equal to the reference value (S221). The reference value is about 1 kph.

If it is determined in S221 that the average differential value of the wheel speeds of the left front and rear wheels FL and RL are all equal to or greater than the reference value, the controller 20 determines that the left turn is made and based on the value of the left turn counter that counts time first. After setting the counter value, a turning flag indicating turning of the vehicle is set (S222). In this case, the reference counter value set in the left turning counter becomes a reference time for determining that the vehicle is not turning when the wheel speed average differential value of the front and rear wheels FL and RL becomes lower than the reference value while the vehicle turns to the right.

After setting the turning flag, the left tire error counter is increased (S224). In operation S225, it is determined whether the counter value of the left tire abnormality is greater than or equal to the reference value. If it is determined in the determination S225 that the left tire abnormality counter value is not equal to or greater than the reference value, the controller 20 resets the tire abnormality flag S230 and returns to the main routine.

On the other hand, if it is determined in step S221 that the wheel speed differential values of the front and rear wheels FL and RL are not all equal to or greater than the reference value, the controller 20 decreases the value of the left turning counter set as the reference counter value in the previous step. (S227). The control unit 20 determines whether the value of the left turn counter is zero after reducing the value of the left turn counter (S228).

If it is determined in step S228 that the value of the left turning counter is zero, the control unit 20 resets the turning flag (S229) and resets the tire abnormality detection flag (S230).

However, if it is determined in step S228 that the value of the left turning counter is not zero, the controller 20 sets the turning flag S223, and maintains the state if the turning flag is already set. And the left tire over the counter to increase (S224).

After the increase of the left tire abnormal counter, it is determined whether the value of the left tire abnormal counter is equal to or greater than the reference value (S225).

If it is determined in the determination S225 that the left tire abnormality counter value is equal to or greater than the reference value, the tire abnormality flag is set (S226). And return to the main routine.

After returning to the main routine, the control unit 20 executes tire abnormality detection. In this case, the control unit 20 executes a tire abnormality detection subroutine S300.

First, the controller 20 calculates an average of deviation values of wheel speeds of the remaining three wheels for each wheel (S301). That is, the controller 20 calculates an average of wheel speed deviation values of the front and rear wheels FR, the rear and rear wheels RL, and the rear and right wheels RR, which are the remaining wheels, with respect to the front and left wheels FL. The wheel deviation average value A of FL) is set. The controller 20 calculates an average of wheel speed deviation values of the front left wheel FL, the rear left wheel RL, and the rear right wheel RR, which are the remaining wheels, with respect to the front right wheel FR. FR) is set to the wheel deviation mean value B.

The controller 20 calculates an average of wheel speed deviation values of the remaining front wheels FR, the front left wheel FL, and the rear right wheel RR with respect to the rear left wheel RL. RL) is set to the wheel deviation average value C. The controller 20 calculates an average of wheel speed deviation values of the remaining front wheels FR, the front left wheel FL, and the rear left wheel RL with respect to the rear right wheel RR. RR) is set to the wheel deviation mean value D.

After setting the wheel deviation average values (A, B, C, D) of each wheel in step S301, the controller 20 determines whether the speed of the current vehicle body is greater than or equal to the reference speed. Determines whether the vehicle speed calculated by the wheel speed is equal to or greater than the first reference speed E km / h (S302).

If it is determined in the determination S302 that the vehicle body speed is equal to or greater than the first reference speed E km / h, the controller 20 sets the second reference speed F kph as the comparison speed H kph (S303). However, if it is determined in the determination S302 that the vehicle body speed is equal to or less than the first reference speed E, the controller 20 sets the third reference speed G kph as the comparison speed H kph (S304).

In this case, the second reference speed F kph is a deviation value of the wheel speed when the body speed is equal to or greater than the first reference speed E km / h, and the third reference speed G kph is the first reference speed E. It is the deviation value of wheel speed when below.

After the comparison speed H kph is set, the control unit 20 compares the wheel deviation average values A, B, C, and D of each of the set wheels with the comparison speed H kph, respectively.

First, the controller 20 determines whether the wheel deviation average value A of the front left wheel FL is faster than the comparison speed H kph (S305). If it is determined in S305 that the wheel deviation average value A of the front wheel FL is faster than the comparison speed H kph, the controller 20 sets an alarm flag S309.

On the other hand, if it is determined in S305 that the wheel deviation average value A of the front left wheel FL is not faster than the comparison speed H kph, the control unit 20 determines that the wheel deviation average value B of the front right wheel FR is the comparison speed. It is determined whether it is faster than (H kph) (S306). If it is determined in the determination S306 that the wheel deviation average value B of the front right wheel FR is faster than the comparison speed H kph, the control unit 20 sets an alarm flag (S309).

However, when it is determined in the determination S306 that the wheel deviation average value B of the front right wheel FR is not faster than the comparison speed H kph, the control unit 20 determines that the wheel deviation average value C of the rear left wheel RL is the comparison speed. It is determined whether it is faster than H kph (S307). If it is determined in the determination S307 that the wheel deviation average value C of the rear wheels RL is faster than the comparison speed H kph, the control unit 20 sets the control flag 20 (S309).

However, if it is determined in the determination S307 that the wheel deviation average value C of the rear wheels RL is not faster than the comparison speed H kph, the controller 20 determines that the wheel deviation average value D of the rear right wheel RR is the comparison speed. It is determined whether it is faster than H kph (S308). If it is determined in the determination S308 that the wheel deviation average value D of the rear right wheel RR is faster than the comparison speed H kph, the control unit 20 sets an alarm flag (S309).

However, if it is determined in the determination S308 that the wheel deviation average value D of the rear right wheel RR is not faster than the comparison speed H kph, the process returns to the main routine.

After returning to the main routine, the controller 20 determines whether the turning flag is set (S410).

If it is determined in step S410 that the turning flag is not set, the control unit 20 determines whether the alarm flag is set (S440). If it is determined in S440 that the alarm flag is set, the control unit 20 drives the alarm unit driving unit 31 to turn on a lamp 32 provided in the instrument panel of the vehicle to visually alert a tire abnormality and to raise the speaker 33. Audible alarm through (S430).

However, if it is determined in step S410 that the turning flag is set, the controller 20 determines whether the tire abnormality flag is set (S420). If it is determined in step S420 that the tire abnormality flag is set, the controller 20 drives the alarm unit driver 31 to light the lamp 32 provided in the instrument panel of the vehicle to visually alert the tire abnormality and to the speaker 33. An audible alarm through the (S430).

As described in detail above, according to the turning and tire abnormality detection method according to the present invention, it is determined whether the wheel speeds of the front and rear wheels of the vehicle are greater than the wheel speeds of the other front and rear wheels, respectively, Is determined to be greater than the wheel speed of the other front and rear wheels, in order to determine whether the vehicle is turning, it is determined whether the differential mean value of the front and rear wheels of the side with the large wheel speed is greater than the reference value of the differential mean value, respectively. If the differential mean value of the wheel is determined to be greater than the reference value, the vehicle is set to turn.If the differential mean value of the front and rear wheels of the side where the wheel speed is constant is not greater than the reference value, respectively, for a predetermined time after the vehicle is set to turn, The tire is set after the vehicle is set to turn. After increasing the value of the counter by detecting the revolution time the time is more than the reference time by an alarm by determining that the Thai above, it is possible to detect the turning over of the vehicle and the tire without adding extra hardware.

Claims (3)

A differential mean value for calculating a mean value of a differential speed calculated in a differential speed calculation step of calculating a differential value of a wheel speed detected in the wheel speed detection step, a wheel speed detection step of detecting a wheel speed, and the differential value calculation step In the tire abnormality detection method comprising a calculation step, A turning judgment step of determining the turning of the vehicle according to the wheel speed of each wheel sensed in the wheel speed detecting step and the average value of the derivative value of each wheel calculated in the derivative mean value calculating step, If the vehicle is determined to turn in the turning judgment step, the tire abnormality determination step to determine whether the tire abnormality by detecting the turning time of the vehicle, Turning and tire abnormality detection method, characterized in that it comprises a warning step for the alarm if it is determined that the tire failure in the tire failure determination step. The method of claim 1, The turning judging step may include a first step of determining whether the wheel speeds of one front and rear wheels of the vehicle are respectively greater than the wheel speeds of the other front and rear wheels, and the wheel speeds of the one front and rear wheels of each of the front and rear wheels are wheels of the other front and rear wheels, respectively. A second step of judging whether the differential mean value of the front and rear wheels of the side having the large wheel speed is greater than the reference value of the differential mean value, respectively, in order to determine whether the vehicle is turned, if it is greater than the speed; If it is determined that the differential mean value of the front and rear wheels is greater than the reference value, the third step of setting the vehicle to turn, and the wheel speed of the second step is continuously increased for a predetermined time after the vehicle is set to turn in the third step. And a fourth step of setting the vehicle not to turn when it is determined that the differential mean value of the front and rear wheels of each side is not larger than the reference value. Turning and tire abnormality detection method characterized in that. The method of claim 1, The tire abnormality determination step includes a counter increment step of increasing a value of a tire abnormality counter, a counter value comparison step of comparing a value of the tire abnormality counter with a reference value for determining a tire abnormality after the counter increase step, and the counter value. And a tire abnormality setting step of setting a tire abnormality if the tire abnormality counter is determined to be equal to or greater than a reference value in the comparing step.