KR101624124B1 - Operation Reliability Improving Method of Smart Parking Assist System - Google Patents

Abstract

The present invention includes a first step S100 of acquiring information necessary for the calculation of the wheel speed, a check value and a sequence number of information necessary for the calculation of the wheel speed which proceeds after the first step S100 (S300), which is a first validity check process performed after a second step (S200) and a second step (S200), of confirming a sequence number And to a method for improving operational reliability of an auxiliary system.
According to the present invention, a reliable wheel can be formed. By using such a wheel, instantaneous oscillation and vibration of electronic power steering (EPS) can be prevented.

Description

Technical Field [0001] The present invention relates to an operation reliability improving method for an automatic parking assist system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel speed calculation method for improving operational reliability of Electronic Power Steering (EPS) when using an automatic parking assist system.

The information that enables the driver to turn on / off when the driver uses the automatic parking assist system uses the vehicle speed transmitted from the engine and the wheel transmitted from the electronic stability control (ESC).

When the driver operates the automatic parking assist system and cares using the accelerator and the brake, the automatic parking assist system does not operate when the vehicle speed increases beyond the prescribed range.

This vehicle speed used by the automatic parking assist system can be satisfied with the automotive safety integrity level (ASIL) D because the vehicle speed itself is sent to the CAN (Controller Area Network) without the check-sum of the vehicle speed none.

For reference, the vehicle speed transmitted from the engine through the current can (CAN) signal and the wheel speed transmitted from the electronic safety control unit (ESC) satisfy the automobile safety integrity level (ASIL) B.

However, in such a conventional automatic parking assist system, the vehicle speed may be distorted due to noise flowing into the vehicle speed that is transmitted to the CAN signal or electromagnetic waves may flow into the CAN line.

In addition, if the wheel speed is not validated, the automatic parking assist system may be inactivated due to an erroneous wheel instantaneously, or the driver might feel instantaneous oscillation and vibration of the EPS (Electronic Power Steering).

When the parking assist system is operated while the wheel is detected at a low speed due to electromagnetic waves and noise flowing in a state of traveling at a high speed, a self-steer in which the steering wheel is automatically operated while the vehicle is operating is operated There is a problem that can cause a big accident.

In addition, since the present vehicle speed and wheel speed received from the current can (CAN) are not check-sum, it is not reliable whether the vehicle speed and the wheel speed are valid values, and the regulations and automobile safety integrity level (ASIL) D There is a problem that can not be satisfied.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for improving operational reliability of a parking assist system in which a vehicle speed and a check-sum received from a can (CAN) will be.

The present invention includes a first step S100 of acquiring information necessary for the calculation of the wheel speed, a check value and a sequence number of information necessary for the calculation of the wheel speed which proceeds after the first step S100 (S300), which is a first validity check process performed after a second step (S200) and a second step (S200), of confirming a sequence number And provides a method for improving operational reliability of the auxiliary system.

The fourth step S400 and the fourth step S400, which are performed when the first validity is satisfied in the third step S300, are checked for the check value and the sequence number through calculation, And a fifth step (S500), which is a second validation process, which proceeds after rough execution.

The present invention proceeds when the secondary effectiveness of the fifth step (S500) is satisfied, and proceeds after the sixth-step S610 and the sixth step S610, which are the wheel speed calculation steps A value representing an absolute value of the difference between the vehicle speed and the vehicle speed that has proceeded after the 6-2 step (S620) and the 6-2 step (S620) of acquiring the calculated vehicle speed from the canned wheel and the can (CAN) (S600), which is a third validation process including step 6-3 (S630), which is a process of determining whether the value exceeds 2KPH (Kilo per Hour).

The present invention is characterized in that the sixth step S610 is a step S611 of obtaining the current and previous pulse counts and a step S611 (Step S612), which is a process of counting the amount of pulse change proceeding after passing through step 6-1-2, and step 6-1-3, which is a process of calculating the distance, Step S613.

The present invention is characterized in that the step of calculating the speed of the vehicle, which is the sixth step S610, is a step of obtaining a present time and a previous time stamp after the step 6-1-3 (S613) 6-1-5 step S615, which is a process of counting the amount of change of the time stamp which proceeds after the step 6-1-4 (S614), and the step 6-1-5 (step S615) S615), which is a process of calculating the time progressed, and a step 6-1-6 (S616) of calculating the time progressed, and a step 6-1-6 (S616) -7 step (S617).

The process of acquiring information necessary for the above-mentioned calculation of the wheel speed includes a wheel pulse count, a total number of pulses connected to the wheel of the vehicle, a circumferential length of the wheel, A Timestamp Count and a Timestamp resolution are obtained.

According to the present invention, a reliable wheel can be formed. By using such a wheel, instantaneous oscillation and vibration of electronic power steering (EPS) can be prevented.

In addition, it is possible to prevent the root cause of the self-steer described as a problem of the related art, thereby enhancing the safety of the driver. In addition, the electronic power steering EPS) can be improved.

In addition, the ASIL D, which is specified in ISO 26262, can be satisfied.

1 is a flowchart showing a method for improving operational reliability of an automatic parking assist system;
2 is a flowchart of a wheel speed calculation;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

FIG. 1 is a flowchart showing a method for improving operational reliability of an automatic parking assist system, and FIG. 2 is a flowchart of a calculation of a wheel speed.

A method for improving operational reliability of an automatic parking assist system according to the present invention includes a first step (S100) of acquiring information necessary for calculating a wheel speed through a starting step, and a second step (S100) of acquiring information necessary for calculating a wheel speed after the first step A second step S200 of checking a check value and a sequence number of the information and a third validation process which is performed after the second step S200, (S400) and a fourth step (S400) of confirming the check value and the sequence number through calculation performed when the first validity is satisfied in the third step (S300) and the third step (S300) A fifth validation step S500 and a sixth validation step S600 in the case where the second validity is satisfied in the fifth step S500, If the third validity is satisfied in the sixth step S600 (S800), which is a process of providing effective information to operate the parking assist system after the seventh step S700 and the seventh step S700, ), A first validity of the third step (S300), a second validity of the fifth step (S500), or a third validity of the sixth step (S600) are unsatisfactory (S1000) of providing the non-operating information of the automatic parking assist system, which is performed after the ninth step (S900) and the ninth step (S900).

In the process of acquiring the information necessary for the calculation of the vehicle speed, which is the first step S100, the following five pieces of information are acquired in order to calculate the wheel speed, and the electronic safety control unit (ESC) ) Communication line to the automatic parking assist system.

The five types of information are: 1. Wheel Pulse Count; 2. the total number of pulses connected to the wheel of the vehicle; 3. the circumferential length of the wheel; Timestamp Count < RTI ID = 0.0 > and 5. < / RTI > Timestamp resolution.

The wheel pulse count is a number that increases as the sensor recognizes a pulse change as the wheel rotates. The Timestamp Count recognizes an increase in pulse and indicates time count information for the increase , And the timestamp resolution indicates time information on the interval of the time stamp count.

When the electronic safety control unit (ESC) sends such information to the can (CAN), it can check whether the information is valid or not, and check value ) And a sequence number.

The second step S200 is a process for checking the five pieces of information, the check value and the sequence number. In this process, the electronic safety controller (ESC) Together with the check value and sequence number, the primary validation of the information exported to CAN is possible.

The check value indicates a value for the five pieces of information, and the sequence number is a number indicating an order in which information is transferred.

The check value and the sequence number are checked in the first validity check of the third step (S300). When the noise and the electromagnetic wave are inputted into the CAN line and the signal is distorted, information necessary for calculating the wheel speed, And the sequence number are distorted together, it is possible to determine the validity of the information by checking the expected check value and the sequence number.

For example, of the values for the five pieces of information, 2. the total number of pulses connected to the wheel of the vehicle, 3. the circumference of the wheel, and 5. the timestamp resolution. It is always a constant value in the same vehicle.

Meanwhile, in the third step S300, if the first validity is satisfied, the fourth step S400 of receiving the validated information is performed so that the check value and the sequence number are valid It is a process of confirming through calculation.

That is, it is checked whether or not the check value indicating the value of the five pieces of information is within a valid range. In addition, it is checked whether the sequence number is transmitted in order.

If the information obtained through the calculation in the fourth step S400 is confirmed as valid information through the second validation step S500, the third validation step S600 is performed.

The sixth step S600 is a step of acquiring the vehicle speed received from the CAN and the calculated wheel speeds after the sixth step S610 and the sixth step S610, If the absolute value of the difference between the vehicle speed and the vehicle speed after step 6-2 (S620) and step 6-2 (S620) exceeds the reference value 2KPH (Kilo per Hour) representing 2 km / h (Step S630).

In the 6-1 step S610, the 5 pieces of information are required. In the 6-1-1 step (S611) of acquiring the current and previous pulse counts through the starting step as shown in FIG. 2 6-1-2 step S612 and step 6-1-2 step S612, which are the steps of counting the amount of pulse change after going through the 6-1-1 step S611, 6-1-3 step S613, which is a process of calculating a distance after a current time, and step 6-1-3, which is a process of acquiring current and previous time stamps after going through the 6-1-3 step S613, Step 6-1-5 (S615), which is a process of counting the amount of change of the time stamp that proceeds after step 4 (S614) and step 6-1-4 (step S614) A process of calculating the wheel speed that proceeds after the sixth through sixth steps S616 and S616, which is a process of calculating the time progressed after the fifth step S615, Step 6-1-7 (S617), step (S618) and (6-1-8) (S618), which are the steps of changing the unit of the wheel in progress after step 6-1-7 (S617) And a termination process.

In the step 6-1-1 (S611), the process of acquiring the current and previous pulse counts is performed for each pulse formed around the wheel, thereby obtaining the current pulse and the previous pulse number.

In the step 6-1-2 (S612), the pulse count is obtained by subtracting the previous pulse from the current pulse.

In the step 6-1-3 (S613), the pulse variation obtained in the step 6-1-2 (S612) is divided by the total number of pulses and the circumferential length (unit: mm) of the wheel is calculated It is a process of multiplying.

Expressed in the equation,

Distance = pulse variation * (1 / number of pulses) * Wheel circumference length

to be.

The process of acquiring the current and previous timestamps in step 6-1-4 (S614) is a process of acquiring a timestamp in the current pulse and a timestamp in the previous pulse.

The process of counting the amount of change of the time stamp in step 6-1-5 (S615) is a process of obtaining a value by subtracting the previous time stamp from the current time stamp.

The process of calculating the time of the step 6-1-6 (S616) is a process of multiplying the time stamp change amount obtained in the step 6-1-5 (S615) by the time stamp resolution (unit: usec).

By expressing this as an equation,

Time = Time stamp change * Timestamp resolution

to be.

The step 6-1-7 (S617) is a process of calculating the wheel speed, and dividing the distance obtained in the step 6-1-3 (S613) by the time obtained in the step 6-1-6 (S616) to be.

In the step of changing the unit of the wheel in the step 6-1-8 (S618), since the unit of the wheel obtained in the step 6-1-7 (S617) is mm / usec, . If necessary, it is converted into Mile / h and used.

Through the above process, the wheel speed of the sixth step S610 is calculated.

In the third step (S300) and the fifth step (S500), the computed value of the two validity tests satisfies the ASIL D defined in ISO26262.

Step 6-2 (S620) is a process of acquiring a vehicle speed transmitted from a wheel and can (CAN) satisfying an ASIL D.

Step 630 is a step of determining whether the difference between the vehicle speed and the vehicle speed exceeds an absolute value of 2 KPH (Kilometer per Hour). If the absolute value exceeds 2 KPH, which is 2 km / h, The process proceeds to a step S900 in which the wheel speed is not calculated. In this case, the third validity test is unsatisfactory in the sixth step S600.

If it is determined in step 630 that the absolute value does not exceed 2KPH per second, the process proceeds to step S700 where the calculated wheel speed is used. In this case, S600), the third validity test is satisfied.

The present invention generates the effect of checking not only the speed of the vehicle but also the stability of the vehicle speed information through the sixth step S600.

According to the present invention, a reliable wheel can be formed. By using such a wheel, instantaneous oscillation and vibration of electronic power steering (EPS) can be prevented.

In addition, it is possible to prevent the root cause of the self-steer described as a problem of the related art, thereby enhancing the safety of the driver. In addition, the electronic power steering EPS) can be improved.

In addition, the ASIL D, which is specified in ISO 26262, can be satisfied.

The foregoing description is merely illustrative of the technical idea of the present invention and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents thereof should be construed as falling within the scope of the present invention.

S100: first step S200: second step
S300: third step S400: fourth step

Claims (8)

A wheel pulse count, a total number of pulses connected to a wheel of the vehicle, a wheel circumference length, a timestamp count, and a timestamp resolution. (S100), which is a process of acquiring information necessary for the calculation of the wheel speed,
A second step S200 of checking a check value and a sequence number of the information necessary for the calculation of the wheel speed,
A third step (S300) of a first validation process of the information necessary for the calculation of the wheel speed, the check value and the sequence number,
A fourth step (S400) of checking the check value and the sequence number when the first validity is satisfied in the third step (S300)
In a fifth step S500, which is a second validity checking process performed after the fourth step S400,
And,
Wherein the check value is a numerical value of information necessary for the calculation of the wheel speed, the sequence number is a sequence of acquiring information necessary for the calculation of the wheel speed,
The third step is to check the validity of the check value and the sequence number using the total number of pulses having a constant value in the same vehicle, the circumference length of the wheel, and the time stamp resolution,
Wherein the fifth step checks validity of the check value and the sequence number by confirming whether the check value is within a valid range and checking whether the sequence number is transmitted in order. delete The method according to claim 1,
And the second validity of the fifth step S500 is satisfied,
Step 6-1 (S610), which is a wheel speed calculation process,
A sixth step S620 of acquiring the calculated vehicle speed and the vehicle speed received from the CAN after the sixth step S610,
(S630), which is a step of determining whether a value representing an absolute value of a difference between a vehicle speed and a vehicle speed that has proceeded after step 6-2 (S620) exceeds a reference value (S600). ≪ RTI ID = 0.0 > [10] < / RTI > The method of claim 3,
In the sixth-first step S610,
A step 6-1-1 (S611) of acquiring the current and previous pulse counts,
A step 6-1-2 (S612) of counting the amount of pulse change proceeding after the step 6-1-1 (S611), and
And a step 6-1-3 (S613) of calculating the distance traveled after the step 6-1-2 (S612). The method for improving the operational reliability of the automatic parking assist system . The method of claim 4,
In the sixth-first step S610,
Step 6-1-4 (S614) of acquiring current and previous time stamps,
Step 6-1-5 (S615), which is a process of counting the amount of change of the time stamp proceeding after the step 6-1-4 (S614)
Steps 6-1-6 (S616), which is a process of calculating the time progressed after the step 6-1-5 (S615), and
(S617), which is a process of calculating a wheel speed that proceeds after the step 6-1-6 (S616). The automatic parking assist system according to claim 6, Way. delete delete delete

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