JP-7855994-B2 - Vehicle control system

JP7855994B2JP 7855994 B2JP7855994 B2JP 7855994B2JP-7855994-B2

Inventors

能村真

Assignees

トヨタ自動車株式会社

Dates

Publication Date: 20260511
Application Date: 20221209

Claims (3)

A vehicle control device having a meter display ECU that calculates the meter display vehicle speed shown on the vehicle's speedometer and a vehicle speed control ECU that controls the vehicle speed of the vehicle, The aforementioned meter display ECU is A GNSS speed acquisition unit that acquires the GNSS speed of the vehicle from the GNSS receiving unit of the vehicle, A gain error calculation unit calculates the gain error of the detected vehicle speed based on the vehicle speed sensor of the vehicle and the GNSS speed, A meter display vehicle speed calculation unit calculates the meter display vehicle speed based on the detected vehicle speed, the gain error, and the offset value, An offset value calculation unit calculates the offset value based on the past gain error calculation results so that the meter-displayed vehicle speed is greater than or equal to the detected vehicle speed and the GNSS speed, Equipped with, The aforementioned vehicle speed control ECU is A display vehicle speed calculation unit calculates the meter display vehicle speed using the gain error and offset value obtained from the meter display ECU and the detected vehicle speed obtained from the vehicle speed sensor. A vehicle control device comprising a vehicle speed control unit that accelerates or decelerates the vehicle so that the meter-displayed vehicle speed becomes a preset target vehicle speed, as a vehicle speed control of the vehicle.
The vehicle control device according to claim 1, wherein the meter display ECU, when the ignition of the vehicle is turned ON, sets the maximum value of the gain error calculated during the previous run as the initial value of the gain error calculated by the gain error calculation unit, and sets the maximum value of the offset value calculated during the previous run as the initial value of the offset value calculated by the offset value calculation unit.
The vehicle control device according to claim 1 or 2, wherein the GNSS speed acquisition unit acquires the GNSS speed from the change in the frequency of the carrier wave from the positioning satellite.

Description

This invention relates to a vehicle control device. Conventionally, Japanese Patent No. 6400450 is known as a technical document relating to vehicle control devices. This publication describes correcting the vehicle speed detected by the vehicle speed sensor using GPS speed calculated based on positioning signals from positioning satellites. Patent No. 6400450 A block diagram showing a vehicle control device according to one embodiment.This graph illustrates the detected vehicle speed, GNSS speed, gain error corrected vehicle speed, and meter-displayed vehicle speed.This flowchart shows an example of the meter display vehicle speed calculation process performed by the meter display ECU.This flowchart shows an example of vehicle speed control processing by a vehicle speed control ECU. The embodiments of the present invention will be described below with reference to the drawings. The vehicle control device 100 shown in Figure 1 is a device mounted on the vehicle that calculates the vehicle speed displayed on the meter and performs vehicle speed control. The vehicle control device 100 comprises a meter display ECU (Electronic Control Unit) 10 that calculates the vehicle speed displayed on the meter and a vehicle speed control ECU (Electronic Control Unit) 20 that performs vehicle speed control. First, let's explain the meter display ECU 10. The meter display ECU 10 is an electronic control unit having a CPU (Central Processing Unit) and a memory unit such as ROM (Read Only Memory) or RAM (Random Access Memory). The meter display ECU 10 implements various functions, for example, by executing a program stored in the memory unit using the CPU. The meter display ECU 10 may be composed of multiple electronic units. The configuration of the vehicle speed control ECU 20 can be similar. As shown in Figure 1, the meter display ECU 10 is connected to the GNSS (Global Navigation Satellite System) receiver 1 and the vehicle speed sensor 2. The GNSS receiver 1 measures the vehicle's position (e.g., latitude and longitude) by receiving a carrier wave (GNSS signal) from positioning satellites. The GNSS receiver 1 transmits the frequency information of the acquired carrier wave to the meter display ECU 10. Note that the GNSS receiver 1 may also be a GPS (Global Positioning System) receiver. The vehicle speed sensor 2 is a detector that detects the vehicle speed. For example, a wheel speed sensor is used, which is mounted on the vehicle's wheels or a drive shaft that rotates integrally with the wheels, and detects the rotational speed of the wheels. The vehicle speed sensor transmits the detected vehicle speed information (e.g., the vehicle speed pulse signal from the wheel speed sensor) to the meter display ECU 10. The vehicle speed sensor also transmits the detected vehicle speed information to the vehicle speed control ECU 20. Next, the functional configuration of the meter display ECU 10 will be described. The meter display ECU 10 includes a GNSS speed acquisition unit 11, a vehicle speed calculation unit 12, a meter correction coefficient calculation unit 13, and a meter display vehicle speed calculation unit 14. The GNSS speed acquisition unit 11 acquires the vehicle's GNSS speed based on the carrier waves of the positioning satellites (GNSS satellites) received by the GNSS receiver unit 1. GNSS speed is the vehicle's speed calculated from the carrier waves of the positioning satellites. The GNSS speed acquisition unit 11 calculates the GNSS speed from the change in the frequency of the received carrier wave due to the Doppler effect. The GNSS speed acquisition unit 11 can calculate the GNSS speed using, for example, the carrier waves of four or more positioning satellites. The vehicle speed calculation unit 12 calculates the detected vehicle speed of the vehicle based on the detected vehicle speed information from the vehicle speed sensor 2. For example, the vehicle speed calculation unit 12 obtains the detected vehicle speed from the vehicle speed pulse signal. The meter correction coefficient calculation unit 13 calculates a meter correction coefficient for calculating the meter-displayed vehicle speed. The meter correction coefficient includes the gain error and the offset value. As shown in Figure 1, the meter correction coefficient calculation unit 13 includes a gain error calculation unit 31 and an offset value calculation unit 32. The gain error calculation unit 31 calculates the gain error of the detected vehicle speed based on the detected vehicle speed and the GNSS speed. The gain error is a coefficient used for calculating the meter-displayed vehicle speed. Errors in the detected vehicle speed occur due to changes in tire diameter and distortion of the drive shaft caused by the vehicle's movement. Therefore, a gain error is calculated to correct the detected vehicle speed using the GNSS speed, which has high accuracy. An example of gain error can be calculated using the formula: GNSS speed = gain error × det