JP2005070982A - Travel controller for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent inaccurate control from being executed when an advancing route of own vehicle is not found accurately. <P>SOLUTION: Whether a vehicular speed is a very low speed or not is determined (S102) in automatic steering of automatic steering control, the advancing route of the own vehicle is estimated (S103) when not in the very low speed, a node on a target advancing route nearest from the present own vehicle position is extracted (S104), and a front-side contemplating distance is found (S105). The node on the target advancing route in the vicinity of the front-side contemplating distance is set thereafter as a guide target node (S106), a lateral shift level of the guide target node from the own vehicle advancing route is computed as a target node deviation (S107), and a target steering wheel angle is calculated thereafter (S108). Then, a steering wheel angle deviation is computed (S109), and a indication current of a motor-driven power steering motor is computed thereafter (S10). The automatic steering is interrupted (S112), when the vehicular speed is the very low speed in the S102. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle for controlling driving of an own vehicle along the target traveling path by automatic steering or automatic steering based on the position of the own vehicle acquired from an artificial satellite, a target traveling path set in a map and the like and the current traveling path of the vehicle The present invention relates to a traveling control apparatus.

  In recent years, GPS (Global Positioning System) that detects the position of a vehicle based on position data obtained from an artificial satellite has been widely used in navigation devices for vehicles, and based on the own vehicle position information detected by this GPS. Various techniques for running control have been proposed and put into practical use.

For example, in Japanese Patent Application Laid-Open No. 2003-26017, the vehicle position is detected based on information from GPS, a target trajectory that is a travel target is calculated, and a forward gaze distance is calculated depending on a steering frequency response. Then, based on the vehicle traveling direction vector, the future position lateral deviation between the host vehicle and the target locus at the forward gaze distance position is calculated, and the current position lateral deviation between the host vehicle and the target locus at the current position is calculated. Then, based on the current position lateral deviation and the future position lateral deviation, the target steering angle change amount for steering the vehicle to follow the target locus is calculated, and the steering is performed with a command value for obtaining the calculated target steering angle change amount. Techniques for performing automatic steering are disclosed.
JP 2003-26017 A

  However, since the technique of the above-mentioned Patent Document 1 calculates the future position lateral deviation based on the own vehicle traveling direction vector, if the own vehicle traveling direction vector is incorrect, the future position lateral deviation is calculated. There is a problem that the deviation cannot be obtained with high accuracy and automatic steering with high accuracy cannot be performed.

  The present invention has been made in view of the above circumstances, and provides a vehicle travel control device that can reliably prevent the execution of inaccurate control when the own vehicle traveling path is not accurately obtained. Objective.

  The present invention relates to a vehicle travel control device for performing travel control of a host vehicle based on information from a satellite orbiting the earth, a host vehicle position calculation means for calculating the host vehicle position based on information from the satellite, Vehicle traveling path estimating means for estimating the traveling path of the vehicle based on a change over time of the vehicle position, target traveling path setting means for setting a target traveling path for the vehicle to travel, the vehicle position and the vehicle Travel control means for executing travel control of the host vehicle according to the vehicle travel path and the target travel path, and when the host vehicle speed is a preset very low speed, the host vehicle travel path is estimated It is characterized by prohibiting.

  The vehicle travel control apparatus according to the present invention can reliably prevent the execution of inaccurate control when the own vehicle traveling path is not accurately obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show an embodiment of the present invention, FIG. 1 is a schematic explanatory view showing the entire vehicle travel control device, FIG. 2 is a flowchart of automatic steering of automatic steering control, and FIG. 3 is a principle of automatic steering. FIG. 4 is an explanatory diagram showing an example of automatic steering when the own vehicle traveling path cannot be accurately estimated.

  As shown in FIG. 1, the present embodiment performs control using a well-known RTK (Real-Time Kinematic) -GPS among GPS forms, and is an artificial satellite (GPS satellite) that orbits the earth. Information from 1 (data including satellite orbit information necessary for positioning calculation etc.) is received by the reference station 2 and the own vehicle 3 as a mobile station.

  The reference station 2 is provided at a point where the position is accurately obtained in advance, and mainly includes a GPS antenna 2a, a GPS receiver 2b, and a radio 2c. Then, the phase information of the radio wave from the GPS satellite 1 observed at the reference station 2, the pseudo distance, and the position coordinates of the reference station 2 are transmitted by the radio device 2c to the positioning vehicle, that is, the own vehicle 3 which is a mobile station. . Specifically, the reference station 2 transmits data such as an error correction amount, a pseudo distance correction amount, and coordinate values to the host vehicle 3.

  A self-vehicle 3 that is a mobile station is equipped with a GPS antenna 3a, a GPS receiver 3b, and a wireless device 3c. Data such as an error correction amount, a pseudo-range correction amount, a coordinate value, and the like from the reference station 2 described above (wireless Data received by the machine 3c) and information from the GPS satellite 1 received by the host vehicle 3 are compared and analyzed in the GPS receiver 3b, so that the host vehicle position (coordinate values) can be obtained immediately and accurately (for example, Error 1-5 cm). Thus, the GPS receiver 3b has a function as a vehicle position calculation means.

  The host vehicle 3 is provided with a control device 3d. A GPS receiver 3b is connected to the control device 3d via a serial-CAN converter or the like (not shown) and current position information is input. Sensors such as a vehicle speed sensor 3e for detecting the vehicle speed V, a handle angle sensor 3f for detecting the handle angle θH, and a main switch 3g for automatic steering control are connected.

  Further, the control device 3d of the host vehicle 3 stores necessary map information in advance on a hard disk (not shown) or a storage medium such as a CD or a DVD. This map information is appropriately displayed on, for example, a liquid crystal display 3h provided on the dashboard, and the driver inputs a destination using a remote control device (not shown), so that the current vehicle position and the destination can be determined from the current position. The optimal course up to (target path: given in node sequence) is displayed on the map.

  In addition, an electric throttle valve control device 3i, a brake control device 3j, and an electric power steering control device 3k are connected to the control device 3d of the host vehicle 3 as actuators that execute automatic steering control.

  When the driver turns on the main switch 3g for autopilot control and the target vehicle speed in the autopilot control is set, the driver outputs a signal to the electric throttle valve control device 3i so as to maintain the target vehicle speed. When 3l is driven to accelerate or decelerate and a large deceleration greater than a predetermined value is performed, a signal is output to the brake control device 3j to activate the automatic brake.

  Next, automatic steering of automatic steering control in the control device 3d of the host vehicle 3 will be described with reference to the flowchart of FIG. 2 and the explanatory diagram of the principle of automatic steering of FIG. The flowchart in FIG. 2 is a program that is executed every predetermined time when the main switch 3g for autopilot control is turned on. First, necessary parameters are read in step (hereinafter abbreviated as “S”) 101. Is called.

  Next, it progresses to S102 and it is determined whether the vehicle speed is very low speed, and when it is not extremely low speed, it progresses to S103 or later.

  In S103, for example, the vehicle positioning point history 5m before the current position is extracted from the past history of the vehicle position, and the vehicle positioning point 5m before and the current vehicle position are connected. Estimate the car traveling path.

  Next, the process proceeds to S104, and the node of the target traveling path that is closest to the current vehicle position is extracted.

  Thereafter, the process proceeds to S105, and the forward gaze distance is obtained from the current host vehicle speed and the preset forward gaze time (for example, 1.5 seconds). For example, when the current vehicle speed is 20 km / h, the forward gaze distance is 5.56 m · 1.5 seconds = 8.34 m.

  Next, the process proceeds to S106, and a node on the target traveling path in the vicinity of the forward gaze distance obtained in S105 is set as the guidance target node.

  Next, proceeding to S107, the lateral deviation from the guidance target node and the own vehicle traveling path is calculated as the target node deviation ΔD.

Next, in S108, the target handle angle δh is calculated by the following formula so that the target node deviation ΔD is zero.
δh = Gp · ΔD + Gd · (d (ΔD) / dt)
Here, Gp is a proportional term gain, and Gd is a differential term gain.

  Next, in S109, a handle angle deviation Δδ (= δh−θH) is calculated from the target handle angle δh and the actual handle angle θH detected by the handle angle sensor 3f.

Next, in S110, the command current Iδ of the electric power steering motor in the electric power steering control device 3k is calculated so that the steering wheel angle deviation Δδ is zero by the following formula, and this command current Iδ is output in S111. Exit the program.
Iδ = Kp · Δδ + Kd · (d (Δδ) / dt) + Ki · ∫Δδdt
Here, Kp is a proportional term gain, Kd is a differential term gain, and Ki is an integral term gain.

  On the other hand, if it is determined in S102 that the vehicle speed is extremely low, the process proceeds to S112, and the automatic steering is stopped and the program is exited. That is, as shown in FIG. 4, when the vehicle speed is extremely low, there are a plurality of positioning points between the own vehicle positioning point 5 meters before and the current vehicle position, and the own vehicle 5 meters before is simply An accurate own vehicle traveling path cannot be estimated by connecting the positioning point and the current vehicle position. In the example of FIG. 4, an error of θe occurs between the own vehicle traveling path estimated by connecting the own vehicle positioning point 5 m before and the current own vehicle position and the actual own vehicle traveling path. . In such a situation where the host vehicle traveling path cannot be accurately estimated, it is preferable to stop the autopilot operation rather than continue on the host vehicle traveling path including the error. Therefore, in the present embodiment, since the host vehicle traveling path is estimated based on the time-dependent change of the host vehicle position, the host vehicle traveling path is estimated when the host vehicle speed is a preset very low speed. By prohibiting it, it is possible to prevent the control with many errors on the contrary. Instead of stopping the autopilot, the autopilot that has been performed up to the previous time may be continued this time.

  Thus, in the present embodiment, the control device 3d of the host vehicle 3 has functions as host vehicle traveling path estimation means, target traveling path setting means, and travel control means.

  Further, in the present embodiment, the description has been given using the example in which the own vehicle traveling path is calculated by connecting the own vehicle positioning point 5 m ahead and the current own vehicle position, but the present invention is not limited to this. That is, the present invention can be applied not only to a fixed distance, but also to a case where calculation is performed using a vehicle positioning point that is a fixed time ago. Specifically, as shown in FIG. 5, even if the current own vehicle positioning data and the positioning data before Δt time are compared, the extremely low speed in FIG. Further, the error of the own vehicle traveling direction vector also becomes large, and the direction cannot be obtained accurately as compared with the case of the normal speed in FIG. Even in this case, it is possible to prohibit the execution of the control with many errors by prohibiting the estimation of the traveling direction of the host vehicle at an extremely low speed.

Schematic explanatory diagram showing the entire vehicle travel control device Flow chart of automatic steering of automatic steering control Illustration of the principle of automatic steering Explanatory drawing which shows an example of the automatic steering when the own vehicle traveling path cannot be estimated accurately Explanatory drawing of the magnitude of the error according to the vehicle speed when estimating the own vehicle traveling path using the own vehicle positioning point before a certain time

Explanation of symbols

1 GPS Satellite 2 Reference Station 2a GPS Antenna 2b GPS Receiver 2c Radio 3 Automobile 3a GPS Antenna 3b GPS Receiver (Own Vehicle Position Calculation Means)
3c wireless device 3d control device (own vehicle travel path estimation means, target travel path setting means, travel control means)
3e Vehicle speed sensor 3f Handle angle sensor 3g Main switch 3h Liquid crystal display 3i Electric throttle valve control device 3j Brake control device 3k Electric power steering control device 3l Throttle valve

Agent Patent Attorney Susumu Ito

Claims (3)

In a vehicle travel control device that performs travel control of the host vehicle based on information from satellites orbiting the earth,
Own vehicle position calculating means for calculating the own vehicle position based on the information from the satellite;
Vehicle traveling path estimation means for estimating the traveling path of the vehicle based on the time-dependent change of the vehicle position
Target travel path setting means for setting a target travel path for the host vehicle to travel;
Travel control means for executing travel control of the host vehicle according to the host vehicle position, the host vehicle traveling path, and the target traveling path;
A traveling control apparatus for a vehicle, wherein when the own vehicle speed is an extremely low speed set in advance, the estimation of the own vehicle traveling path is prohibited.   2. The travel control apparatus for a vehicle according to claim 1, wherein the own vehicle traveling path estimation means estimates the traveling path of the own vehicle based on a current position of the own vehicle and a position of the own vehicle before a predetermined distance.   2. The travel control apparatus for a vehicle according to claim 1, wherein the own vehicle traveling path estimating means estimates the own vehicle traveling path based on the current position of the own vehicle and the own vehicle position before a predetermined time.

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