KR20210049761A - Device for vehicle speed correction and method of calculating the wheel scale factor by the same - Google Patents

Abstract

Disclosed are a vehicle speed correcting device and a speed correction coefficient calculating method thereby. According to an aspect of the present invention, the vehicle speed correcting device comprises: a measuring unit configured to measure a first speed value through a sensor of a vehicle; an obtaining unit for obtaining a second speed value of the vehicle from a satellite; a determining unit for determining whether to perform a correction coefficient calculating operation; a calculating unit for calculating a correction coefficient for correcting the speed values of the vehicle by inputting a calculation value, generated based on the first speed value and the second speed value, to a Kalman filter based on a determination result of the determining unit; and a correcting unit configured to correct the speed of the vehicle by multiplying the correction coefficient by the first speed value.

Description

Device for vehicle speed correction and method of calculating the wheel scale factor by the same}

The present invention relates to a vehicle speed correction apparatus, and more particularly, to a technique for calculating a correction coefficient for speed correction.

In general, in order to measure the vehicle speed, a control unit of a vehicle uses information from a wheel speed sensor mounted on a wheel. At this time, the wheel speed sensor outputs a wheel speed signal that periodically changes according to the movement of a tone wheel mounted on the wheel. This wheel speed signal changes its cycle according to the vehicle's speed.

For example, when the vehicle travels at high speed, the cycle of the wheel speed signal is shortened. On the other hand, when the vehicle is traveling at a low speed, the cycle of the wheel speed signal output from the sensor becomes relatively longer than when the vehicle is traveling at high speed.

The control unit measures the period of the wheel speed signal provided from the wheel speed sensor, and calculates the vehicle speed according to the magnitude of the period. However, slipping occurs depending on conditions such as the number of revolutions of the wheel, temperature, aging of the wheel, and road surface condition, and thus measuring the vehicle speed using only the wheel speed signal is inferior.

Meanwhile, information on the location, speed, and time of a vehicle may be obtained from GPS satellites using a global positioning system (GPS). However, in an urban area or a mountainous area, a section in which the number of visible satellites of GPS is less than 3 may occur due to buildings or trees. In such a section, since the precision of the location information is low, it is not possible to know the exact location of a stable vehicle. In addition, since the GPS reception period is slow, a fast periodic vehicle location update (update) for vehicle control is required.

Recently, in order to determine the position of a vehicle in a fast cycle, information on a vehicle's position is improved using information from a wheel speed sensor and GPS information, and this is called dead reckoning (DR). However, since conventional speculative navigation uses the wheel speed signal provided by the wheel speed sensor as it is, an error may occur depending on conditions such as the number of rotations of the wheel, temperature, aging degree of the wheel, and road surface conditions. In addition, since a delay time occurs in receiving location information from a GPS satellite, a time error occurs between the information received from the GPS and the information received from the sensor at the present time, resulting in inferior accuracy.

An object of the present invention is to provide a technical method for correcting a vehicle speed using a vehicle speed received from a satellite and a correction coefficient calculated using a vehicle speed measured through a sensor.

A vehicle speed correction apparatus according to an aspect of the present invention for achieving the above-described problem includes a measurement unit measuring a first speed value through a sensor of a vehicle, an acquisition unit obtaining a second speed value of the vehicle from a satellite, and correction A determination unit that determines whether a coefficient calculation operation is in progress, and corrects the vehicle speed value by inputting an operation value generated based on the first speed value and the second speed value into the Kalman filter based on the determination result of the determination unit. And a calculation unit that calculates a correction coefficient for calculating a correction coefficient and a correction unit that multiplies the correction coefficient and the first speed value to correct the speed of the vehicle, wherein the operation of calculating the correction coefficient is not performed by the determination unit. If determined, the correction unit corrects the first speed value using a correction coefficient calculated in a previous period.

Meanwhile, a method of calculating a vehicle speed correction coefficient for correcting a vehicle speed according to another aspect of the present invention for achieving the above-described problem includes the steps of measuring a first speed value using a wheel sensor of the vehicle, and a Global Positioning System (GPS). ) Obtaining a second speed value of the vehicle from a satellite, determining whether a correction coefficient calculation operation is in progress, and calculating a calculation value generated based on the first speed value and the second speed value based on the determination by Kalman Comprising the step of calculating a correction coefficient for correcting the speed value of the vehicle by inputting into a filter, and correcting the speed of the vehicle by multiplying the correction coefficient and the first speed value, and based on the determination If it is determined that the correction coefficient calculation operation is not in progress, the step of correcting the first speed value using a correction coefficient calculated in a previous period is further included,

The vehicle speed correction apparatus according to an embodiment of the present invention uses previously used wheel acceleration information and GPS information, and thus dead reckoning can be implemented without additional hardware, thereby reducing cost.

In addition, the vehicle speed correction apparatus according to an embodiment of the present invention calculates a WheelScale Factor in consideration of a data reception delay time from GPS when using the wheel speed of the vehicle and the GPS speed, and uses the vehicle speed correction device. By correcting the speed of the vehicle, it has a positive effect on the performance improvement of the guessing navigation and the positioning of the autonomous vehicle.

Further, the vehicle speed correction apparatus according to an embodiment of the present invention determines whether to proceed with the correction coefficient calculation operation in consideration of the reception sensitivity of GPS and the speed of the corrected vehicle, and then calculates the correction coefficient, thereby calculating the correction coefficient. The accuracy of vehicle speed correction and travel distance calculation is improved.

1 is a block diagram of a vehicle speed correction apparatus according to an embodiment of the present invention.
2 is a view for explaining a buffer of a vehicle speed correction apparatus according to an embodiment of the present invention.
3 is a flowchart illustrating a method of calculating a speed correction coefficient by a vehicle speed correction device according to an embodiment of the present invention.

The above-described and other objects, advantages, and features of the present invention, and methods of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the following embodiments are the object of the invention to those of ordinary skill in the art to which the present invention pertains. It is only provided to easily inform the composition and effect, and the scope of the present invention is defined by the description of the claims.

Meanwhile, terms used in the present specification are for explaining embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification, "comprises" and/or "comprising" refers to the presence of one or more other components, steps, operations and/or elements in which the referenced component, step, operation and/or element is Or does not preclude additions.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to elements of each drawing, the same elements are assigned the same reference numerals as much as possible, even if they are indicated on different drawings, and in describing the present invention, specific reference numerals for related known configurations or functions If the description may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

It is not possible to determine the exact speed of the vehicle only by using the vehicle sensor, and accordingly, the actual moving distance of the vehicle cannot be accurately determined. Accordingly, in order to determine a stable vehicle position, the vehicle speed correction apparatus according to an embodiment of the present invention performs dead reckoning (DR) to improve vehicle position information by using the wheel speed sensor information and GPS information.

In this case, the vehicle speed correction apparatus according to an embodiment of the present invention calculates a correction coefficient using information obtained from a satellite together with a vehicle sensor, and corrects a vehicle speed value using the calculated correction coefficient. By accurately determining the vehicle speed through such a process, the actual moving distance of the vehicle can also be accurately identified.

To this end, the vehicle speed correction apparatus according to an embodiment of the present invention includes a configuration as shown in FIG. 1. As shown in FIG. 1, the vehicle speed correction apparatus 100 according to an exemplary embodiment of the present invention includes a measurement unit 110, an acquisition unit 120, a calculation unit 140, and a determination unit 150.

The measurement unit 110 measures a first speed value through a sensor of the vehicle. Here, the vehicle sensor is an In Vehicle Sensor (IVS), which is a wheel speed sensor. The wheel speed sensor is mounted on the left and right rear wheels of the vehicle, and outputs a wheel speed signal that changes periodically according to the movement of the tone wheel. For example, the wheel speed sensor outputs a signal through the vehicle's CAN (C-CAN) communication.

The measurement unit 110 measures a first speed value of the vehicle using the wheel speed signal output from the wheel speed sensor. For example, the measurement unit 110 measures a first speed value of the vehicle by obtaining a wheel speed signal every first time period (eg, 20 ms) from the wheel speed sensor. The moving distance of the vehicle may be obtained through the measured first speed value.

The acquisition unit 120 acquires a second speed value of the vehicle by using the location information of the vehicle received from the satellite. Here, the satellite is a Global Positioning System (GPS) satellite, and the acquisition unit 120 may be a data adapter such as a GPS module.

In general, the acquisition unit 120 acquires a second speed value through position information of a vehicle received from four or more GPS satellites. At this time, the acquisition unit 120 acquires a second speed value through vehicle location information received from a GPS satellite every second time period (eg, 100 ms).

Although it is preferable that the acquisition unit 120 receives location information from a GPS satellite, it is obvious that other methods of receiving location information may be adopted. In addition, the acquisition unit 120 may acquire the number of communicable GPS satellites, a GPS mode, and a horizontal dilution of precision (HDOP) together with the second speed value.

Meanwhile, the first speed value measured by the measurement unit 110 and the second speed value obtained by the acquisition unit 120 are stored in a buffer. In this case, the first speed value and the second speed value are stored in the buffer 130 in consideration of the reception delay time of the second speed value. This is because the reception delay time of the second speed value exists as the location information is processed from the GPS satellite and is delayed by a predetermined delay time until export, and there is a time difference between the first speed value and the second speed value. .

For example, if the current time point t is 0 ms and the reception time delay time is 60 ms, as shown in FIG. 2, the buffer 130 has an array of size 9 from 160 ms (t-60 ms-100 ms) before the current time ( The first speed value up to 0 ms) is stored every first time (20 ms). Here, 100 ms is a second time period in which the second speed value is obtained.

In addition, in the buffer 130, a second speed value from 100 ms (t-100 ms) to the current time point (0 ms) is stored in an array having a size of 2 every second time period (100 ms). At this time, since there is a reception delay time in the second speed value, each of the second speed values acquired at the current time point (0ms) and the previous period (-100ms) is actually measured between the time point of -160ms and the time point of -60ms. Is the speed value.

The calculation unit 140 calculates a wheel scale factor by using the first speed value and the second speed value stored in the buffer 130. This is because the size of the vehicle's wheels, tires, etc. is not constant, and the wheel is idle on a slippery road surface, so that there is an error between the first speed value measured through the measurement unit 110 and the actual speed of the vehicle. Because it can exist. Accordingly, the calculation unit 140 calculates a correction coefficient for correcting the first speed value.

The calculation unit 140 calculates a correction coefficient using an operation value (measured value) obtained by calculating the first speed value and the second speed value. That is, the calculation unit 140 may calculate a value obtained by dividing the second speed value by the first speed value as a wheel scale factor (correction coefficient).

In another embodiment, the calculation unit 140 inputs the calculation result (measured value) of calculating the first and second speed values into the Kalman filter, and corrects the output value (estimated value) output through the algorithm of the Kalman filter. It is calculated by coefficient.

Here, the Kalman filter algorithm consists of two steps: time information update and measurement information update. These two steps are represented by Equation 1 and Equation 2, respectively.

는 보정 계수 즉, 출력값(추정값)이고,

는 연산값(측정값)이고,

는 Covariance이고,

는 Kalman Gain이며, Q와 R은 노이즈이다.here,

Is the correction factor, that is, the output value (estimated value),

Is the calculated value (measured value),

Is Covariance,

Is Kalman Gain, and Q and R are noise.

Meanwhile, the calculation value (measured value) input to the Kalman filter is obtained through the following process.

)을 구한다. 예컨대, 산출부(140)는 현재 시점(t=0ms)에 획득된 제2 속도값과 현재 시점(t=0ms)에 측정된 제1 속도값을 나눗셈 연산한 결과(

=제2 속도값/제1 속도값)를 연산값으로 구하여 칼만 필터에 입력한다. 이에 따라, 산출부(140)는 칼만 필터의 출력값(

)을 보정 계수로 산출한다.As an example, the calculation unit 140 calculates the second speed value and the first speed value obtained at the current time point t to calculate the calculated value (

). For example, the calculation unit 140 divides the second speed value obtained at the current time point (t=0ms) and the first speed value measured at the current time point (t=0ms) and calculates the result (

=2nd speed value/first speed value) is calculated as an operation value and input into the Kalman filter. Accordingly, the calculation unit 140 is the output value of the Kalman filter (

) Is calculated as a correction factor.

)을 구한다. 예컨대, 산출부(140)는 일정 시간 동안의 제1 속도값의 평균과 일정 시간 동안의 제2 속도값의 평균을 나눗셈 연산하여 연산값을 구한다. 이때, 일정 시간 동안의 제1 속도값 및 제2 속도값은 버퍼(130)에 저장된 것이다.As another example, the calculation unit 140 considers that the period for measuring the first speed value and the period for obtaining the second speed value are different from each other, and the calculation value (

). For example, the calculation unit 140 calculates the calculated value by dividing the average of the first speed values for a certain time and the average of the second speed values for a certain time. At this time, the first speed value and the second speed value for a predetermined time are stored in the buffer 130.

It is assumed that the acquisition period of the second rate value, which has a relatively longer acquisition period of the rate value than the first rate value, is 100 ms. The calculation unit 140 is every 20 ms (-100ms, -80ms, -60ms, -40ms, -20ms, 0ms) for a predetermined period (100ms (-100ms ~ 0ms)) based on the current time point (t=0ms). Calculate the average of the measured first speed values. At this time, 20ms is a time period preset by the user and can be changed. In addition, the calculation unit 140 calculates an average of the second speed value obtained at the current time point (t=0ms) and the second speed value obtained at the previous period (-100ms) based on the current time point t.

=제2 속도값 평균/제1 속도값 평균)를 칼만 필터에 입력한다. 이에 따라, 산출부(140)는 칼만 필터의 출력값(

)을 보정 계수로 산출한다. The calculation unit 140 divides the average of the first speed value and the average of the second speed value obtained as described above, and the result of the operation (

= Average of the second velocity value/average of the first velocity value) into the Kalman filter. Accordingly, the calculation unit 140 is the output value of the Kalman filter (

) Is calculated as a correction factor.

As another example, the calculation unit 140 calculates an operation value in consideration of the reception delay time of the second speed value. Here, it is assumed that the reception time delay time is 60 ms. For example, in the case of acquiring location information through a GPS module, since it takes about 60 ms for the GPS receiver to process the satellite signal and output the location information, it is desirable to consider this time delay.

In this case, the calculation unit 140 operates every 20 ms (-160, -140ms, -120ms, -100ms, -) for a predetermined time (100ms) before the reception delay time (-60ms) based on the current time (t=0ms). 80ms, -60ms) Calculate the average of the measured first speed values. In addition, the calculation unit 140 obtains an average of the second speed values obtained at the current time point (0 ms) and the previous period (-100 ms). Here, since each of the second speed values acquired at the current time point (0ms) and the previous cycle (-100ms) is actually a speed value measured at a time point of -160ms and a time point of -60ms based on the current time point (0ms), The second speed value is also the speed value measured from the time point of -160 ms to the time point of -60 ms is used.

= 일정 시간 동안의 제2 속도값 평균/수신 지연 시간이 고려된 일정 시간 동안의 제1 속도값 평균)를 구하여 보정 계수를 구한다. The calculation unit 140 divides the average of the first speed value and the average of the second speed value in consideration of the thus obtained reception delay time (

= The average of the second speed value for a certain time/average of the first speed value for a certain time considering the reception delay time) is calculated to obtain a correction factor.

= 일정 시간 동안의 제2 속도값 평균/수신 지연 시간이 고려된 일정 시간 동안의 제1 속도값 평균)를 칼만 필터에 입력한다. 산출부(140)는 연산된 연산값(측정값)을 칼만 필터에 입력하며, 그에 대응하여 출력되는 출력값(예측값)(

)을 보정 계수(Wheel Scale Factor)로 산출한다. 이에 따라, 이전 주기에 산출된 보정 계수(

)는 새로운 보정 계수(

)로 갱신된다.Alternatively, in order to obtain a more accurate statistical predicted value, the calculation unit 140 may perform the calculation result (

= The average of the second speed value for a certain time/the average of the first speed value for a certain time in which the reception delay time is considered) is input into the Kalman filter. The calculation unit 140 inputs the calculated calculation value (measured value) to the Kalman filter, and an output value (predicted value) output corresponding thereto (

) Is calculated as the Wheel Scale Factor. Accordingly, the correction factor calculated in the previous cycle (

) Is the new correction factor (

).

)를 이용하여 보정한다. 예컨대, 보정부(160)는 보정 계수와 제1 속도값을 곱셈 연산하여 차량의 속도값을 보정한다. The correction unit 160 corrects the vehicle speed value using the correction coefficient calculated by the calculation unit 140. At this time, the correction unit 160 calculates the first speed value measured by the measurement unit 110 by a correction factor (

) To correct. For example, the correction unit 160 corrects the vehicle speed value by multiplying the correction coefficient and the first speed value.

)과 이전 주기에서 산출된 보정 계수(

)의 차이가 기 설정된 소정값 이상이면, 보정 계수 산출 동작을 진행하지 않는 것으로 판단한다. 여기서, 소정값은 사전에 사용자에 의해 설정된 값일 수 있다. Meanwhile, before the correction coefficient is calculated by the calculation unit 140, it is determined whether or not to proceed with the correction coefficient calculation operation by the determination unit 150. For example, the determination unit 150 is an operation value input to the Kalman filter (

) And the correction factor (

If the difference between) is greater than or equal to a preset predetermined value, it is determined that the correction coefficient calculation operation is not performed. Here, the predetermined value may be a value previously set by the user.

When the first speed value is less than the predetermined speed value, the determination unit 150 determines that the correction coefficient calculation operation is not performed. This is because when the vehicle is less than a certain speed value (eg, 0.01 m/s), the vehicle is considered to be stopped or slowing, and the effect of correction of the first speed value is insufficient.

The determination unit 150 determines that the correction coefficient calculation operation is not performed when the number of GPS satellites is less than a predetermined number (eg, 3) or when the GPS mode is 0 (when GPS satellites do not exist). This is because the reliability of the second speed value obtained from the GPS satellite is degraded because the GPS reception sensitivity is lowered by the surrounding environment such as buildings, trees, mountains, hills, etc., and the correction coefficient calculated using this is also difficult to trust. to be. At this time, the determination unit 150 determines the reliability of the GPS signal in consideration of the number of GPS satellites acquired from the acquisition unit 120, a GPS mode, and HDOP.

)를 이용하여 보정한다. 또한, 이와 같은 과정을 통해, 보정된 차량의 속도를 이용하여 보정부(160)는 차량의 이동 거리를 계산할 수 있다. If, by the determination unit 150, it is determined that the correction coefficient calculation operation is not performed, the calculation unit 140 does not proceed with the correction coefficient calculation operation. In addition, if it is determined that the correction coefficient calculation operation is not performed by the determination unit 150, the correction unit 160 calculates the first speed value in the previous period.

) To correct. In addition, through such a process, the correction unit 160 may calculate the moving distance of the vehicle by using the corrected vehicle speed.

As described above, the vehicle speed correction apparatus according to an embodiment of the present invention uses previously used wheel acceleration information and GPS information, so that dead reckoning can be implemented without additional hardware, resulting in cost reduction. have.

In addition, the vehicle speed correction apparatus according to an embodiment of the present invention calculates a WheelScale Factor in consideration of a data reception delay time from GPS when using the wheel speed of the vehicle and the GPS speed, and uses the vehicle speed correction device. By correcting the speed of the vehicle, it has a positive effect on the performance improvement of the guessing navigation and the positioning of the autonomous vehicle.

Further, the vehicle speed correction apparatus according to an embodiment of the present invention determines whether to proceed with the correction coefficient calculation operation in consideration of the reception sensitivity of GPS and the speed of the corrected vehicle, and then calculates the correction coefficient, thereby calculating the correction coefficient. The accuracy of vehicle speed correction and travel distance calculation is improved.

3 is a flowchart illustrating a method of calculating a speed correction coefficient by a vehicle speed correction apparatus according to an exemplary embodiment of the present invention.

In step S310, the vehicle speed correction apparatus 100 measures a first speed value through a sensor of the vehicle.

Here, the vehicle sensor is an In Vehicle Sensor (IVS), which is a wheel speed sensor. For example, the vehicle speed correction apparatus 100 measures a first speed value of the vehicle by obtaining a wheel speed signal every first time period (eg, 20 ms) from the wheel speed sensor.

In step S320, the vehicle speed correction apparatus 100 acquires a second speed value through a GPS satellite.

Here, the satellite is a Global Positioning System (GPS) satellite, and the vehicle speed correction apparatus 100 acquires a second speed value through a GPS module. In addition, the vehicle speed correction apparatus 100 may acquire the number of communicable GPS satellites, a GPS mode, and a horizontal dilution of precision (HDOP) together with the second speed value.

Meanwhile, the vehicle speed correction apparatus 100 stores the first speed value and the second speed value in the buffer 130. In this case, the first speed value and the second speed value are stored in the buffer 130 in consideration of the reception delay time of the second speed value. This is because the reception delay time of the second speed value exists as the reception delay time of the second speed value exists, and there is a time difference between the first speed value and the second speed value as it is delayed by a predetermined reception delay time until the location information is processed and exported from the GPS satellite. to be.

For example, if the current time point t is 0 ms and the reception time delay time is 60 ms, as shown in FIG. 2, the buffer 130 has an array having a size of 9 from -160 ms based on the current time point (0 ms). The first speed value up to the time point (0ms) is stored every first time (20ms).

In addition, in the buffer 130, a second speed value from -100 ms before the current time (0 ms) to the current time (0 ms) is stored in an array having a size of 2 every second time period (100 ms). At this time, since a reception delay time exists in the second speed value, each of the second speed values acquired at the current time point (0 ms) and the previous cycle (-100 ms) is actually measured at the time point of -160 ms and the time point of -60 ms. It's the speed value.

In step S330, the vehicle speed correction apparatus 100 determines whether to proceed with the correction coefficient calculation operation.

)과 이전 주기에서 산출된 보정 계수(

)의 차이가 기 설정된 소정값 이상인 경우, 제1 속도값이 일정 속도값(예컨대, 0.01m/s) 이하인 경우, GPS 위성의 개수가 소정 개수(예컨대, 3개) 이하이거나 GPS 모드가 0인 경우(GPS 위성이 존재하지 않은 경우) 중 적어도 하나의 경우 보정 계수 산출 동작을 진행하지 않는 것으로 판단한다. In this case, the case where the correction coefficient calculation operation is not performed may be as follows. For example, the vehicle speed correction apparatus 100 may be configured with an operation value input to the Kalman filter (

) And the correction factor (

) Is greater than or equal to a preset value, the first speed value is less than or equal to a certain speed value (eg, 0.01m/s), the number of GPS satellites is less than a certain number (eg, 3) or the GPS mode is 0. In at least one of the cases (when there is no GPS satellite), it is determined that the correction coefficient calculation operation is not performed.

If it is determined that the correction coefficient calculation operation is performed in step S330, the vehicle speed correction apparatus 100 calculates and updates the correction coefficient using the first speed value and the second speed value in step S340.

)를 칼만 필터에 입력하며, 칼만 필터의 알고리즘을 통해 출력되는 출력값(추정값)(

)을 보정 계수로 산출한다. For example, the vehicle speed correction apparatus 100 may calculate a first speed value and a second speed value, and the calculation result (measured value) (

) To the Kalman filter, and the output value (estimated value) that is output through the Kalman filter's algorithm (

) Is calculated as a correction factor.

Here, the vehicle speed correction apparatus 100 calculates an operation value in consideration of the reception delay time of the second speed value. Here, it is assumed that the predetermined reception time delay time is 60 ms.

The vehicle speed correction device 100 is based on the current time (t=0ms), and every 20ms (-160, -140ms, -120ms, -100ms, -80ms) for a certain time (100ms) before the reception delay time (-60ms). , -60ms) Calculate the average of the measured first speed values. In addition, the vehicle speed correction apparatus 100 obtains an average of the second speed values obtained at the current time point (0 ms) and the previous period (-100 ms).

= 일정 시간 동안의 제2 속도값 평균/수신 지연 시간이 고려된 일정 시간 동안의 제1 속도값 평균)를 칼만 필터에 입력한다.The vehicle speed correction apparatus 100 divides the average of the first speed value and the average of the second speed value in consideration of the received delay time obtained as described above.

= The average of the second speed value for a certain time/the average of the first speed value for a certain time in which the reception delay time is considered) is input into the Kalman filter.

)를 이용하여 차량의 속도를 보정한다. In step S350, the vehicle speed correction device 100 is the correction coefficient calculated in step S340 (

) To correct the vehicle's speed.

)를 이용하여 보정한다. 예컨대, 차량 속도 보정 장치(100)는 보정 계수(

)와 제1 속도값을 곱셈 연산하여 차량의 속도값을 보정한다. At this time, the vehicle speed correction apparatus 100 calculates the first speed value measured at the current time point (t=0ms) by a correction factor (

) To correct. For example, the vehicle speed correcting device 100 may have a correction factor (

) And the first speed value are multiplied to correct the vehicle speed value.

)를 이용하여 차량의 속도를 보정한다. If, in step S330, if it is determined that the correction coefficient calculation operation is not in progress, the vehicle speed correction apparatus 100 performs a correction coefficient calculated in the previous cycle (

) To correct the vehicle's speed.

)를 이용하여 차량의 속도를 보정한다. At this time, the vehicle speed correction device 100 uses the first speed value measured at the current time point (t=0ms) and a correction factor calculated in the previous cycle (

) To correct the vehicle's speed.

As described above, the vehicle speed correction apparatus according to an embodiment of the present invention uses previously used wheel acceleration information and GPS information, so that dead reckoning can be implemented without additional hardware, resulting in cost reduction. have.

In addition, the vehicle speed correction apparatus according to an embodiment of the present invention calculates a WheelScale Factor in consideration of a data reception delay time from GPS when using the wheel speed of the vehicle and the GPS speed, and uses the vehicle speed correction device. By correcting the speed of the vehicle, it has a positive effect on the performance improvement of the guessing navigation and the positioning of the autonomous vehicle.

Further, the vehicle speed correction apparatus according to an embodiment of the present invention determines whether to proceed with the correction coefficient calculation operation in consideration of the reception sensitivity of GPS and the speed of the corrected vehicle, and then calculates the correction coefficient, thereby calculating the correction coefficient. The accuracy of vehicle speed correction and travel distance calculation is improved.

Above, the configuration of the present invention has been described in detail through a preferred embodiment of the present invention, but those of ordinary skill in the art to which the present invention pertains, the present invention is disclosed in the present specification without changing the technical idea or essential features. It will be appreciated that it may be implemented in a specific form different from that of. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects. The scope of protection of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

100: vehicle speed correction device
110: measurement unit 120: acquisition unit
130: buffer 140: calculation unit
150: determination unit 160: correction unit

Claims (10)

A measuring unit that measures a first speed value through a sensor of the vehicle;
An acquisition unit that acquires a second speed value of the vehicle from a satellite;
A determination unit that determines whether a correction coefficient calculation operation is in progress;
A calculation unit for calculating a correction coefficient for correcting the vehicle speed value by inputting an operation value generated based on the first speed value and the second speed value into the Kalman filter based on the determination result of the determination unit; And
And a correction unit for multiplying the correction coefficient and the first speed value to correct the speed of the vehicle,
When it is determined by the determination unit that the correction coefficient calculation operation is not performed, the correction unit corrects the first speed value using a correction coefficient calculated in a previous period.
In-vehicle speed correction device
The method of claim 1, wherein the calculation unit,
Calculating the calculation value obtained by dividing the second speed value by the first speed value and calculating the correction coefficient
Vehicle speed correction device.
The method of claim 1, wherein the calculation unit,
Divide the average of the first speed values measured for a certain time before the reception delay time and the average of the second speed values obtained for the certain time, and calculate the correction coefficient as an operation value that is a result of the division operation. To produce
Vehicle speed correction device.
The method of claim 1, wherein the measuring unit,
Measuring the first speed value using wheel rotation data obtained by the vehicle wheel sensor
Vehicle speed correction device.
The method of claim 1, wherein the acquisition unit,
Acquiring the second speed value from a Global Positioning System (GPS) satellite
Vehicle speed correction device.
In the vehicle speed correction coefficient calculation method for vehicle speed correction,
Measuring a first speed value using a vehicle wheel sensor;
Obtaining a second speed value of the vehicle from a Global Positioning System (GPS) satellite;
Determining whether a correction coefficient calculation operation is in progress;
Calculating a correction coefficient for correcting the speed value of the vehicle by inputting an operation value generated based on the first speed value and the second speed value based on the determination into a Kalman filter; And
Compensating the speed of the vehicle by multiplying the correction coefficient and the first speed value
Including,
If it is determined that the correction coefficient calculation operation is not performed based on the determination, correcting the first speed value using a correction coefficient calculated in a previous period.
How to calculate the vehicle's speed correction factor.
The method of claim 6, wherein calculating the correction coefficient,
Inputting the result of the division operation of the second speed value and the first speed value into the Kalman filter
How to calculate the speed correction factor of the vehicle.
The method of claim 6, wherein calculating the correction coefficient,
Considering the reception delay time of the preset second speed value, using the first speed value acquired in a certain section prior to the reception delay time based on the current time point
How to calculate the speed correction factor of the vehicle.
The method of claim 6,
Obtaining an average of the first speed values measured over a predetermined period of time;
Obtaining an average of the second speed values acquired during the predetermined period of time;
Including,
The step of calculating the correction coefficient,
Inputting the result of dividing the average of the first speed value and the average of the second speed value into the Kalman filter
How to calculate the speed correction factor of the vehicle.
The method of claim 9, wherein the step of obtaining the average of the first speed values,
In consideration of the reception delay time of the preset second speed value, obtaining an average of the first speed values measured for the predetermined time before the reception delay time based on the current point in time
How to calculate the speed correction factor of the vehicle.

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