JP7198005B2 - Vehicle position detector - Google Patents

Description

The present invention relates to a vehicle position detection device that detects the position of a vehicle with respect to a lane using satellite navigation and map information.

Positioning technology using satellite navigation such as GNSS is known as a technology used for driving assistance of a vehicle, as disclosed in Japanese Unexamined Patent Application Publication No. 2007-85909, for example. In addition, by using high-precision satellite navigation positioning, it is possible to detect the position of the vehicle relative to the lane based on the results of comparison between the map information and the positioning results. .

JP 2007-85909 A

In satellite navigation, the positioning error may change greatly due to changes in the number of satellites from which signals can be received. Therefore, when detecting the position of the vehicle with respect to the lane using only the positioning results of satellite navigation, it is necessary to suppress the influence of changes in positioning errors.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems and to provide a vehicle position detecting device that can cope with changes in the magnitude of errors contained in positioning results of satellite navigation.

A vehicle position detection device according to one aspect of the present invention is mounted in a vehicle including a satellite navigation unit that performs positioning using a satellite positioning system and a map information output unit that outputs map information. A vehicle position detection device for calculating, based on the map information, a cross-lane lateral position indicating the lateral position of the vehicle with respect to the center line of the lane in which the vehicle is traveling, wherein the positioning of the satellite navigation unit During a period in which the error is equal to or less than a predetermined threshold, the lateral position relative to the lane is calculated based on a direct comparison result between the positioning result of the satellite navigation unit and the map information, and the positioning error of the satellite navigation unit is a predetermined value. During the period when the threshold is exceeded , the lateral position against the lane last calculated with the positioning error being equal to or less than the predetermined threshold is used as a reference position, and the reference position is obtained from the positioning result by the satellite navigation unit. The lateral position relative to the lane is calculated by adding the integrated result of the relative lateral movement amount of the vehicle.

According to the present invention, it is possible to provide an own vehicle position detecting device that can cope with changes in the magnitude of errors contained in positioning results of satellite navigation.

1 is a configuration diagram of a travel control system; FIG. 4 is a flowchart showing processing for calculating a lateral position against the lane;

Preferred embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following explanation, the scale of each component is changed in order to make each component recognizable on the drawing. is not limited only to the quantity of components, shapes of components, size ratios of components, and relative positions of components described in .

In FIG. 1, reference numeral 1 denotes a travel control system for a vehicle such as an automobile, which performs travel control including autonomous automatic driving of the vehicle. Hereinafter, the vehicle on which the cruise control system 1 is mounted is called the own vehicle.

The self-vehicle includes an operation unit 201 for the driver to perform driving operations. The operation unit 201 includes an accelerator pedal 201a, a brake pedal 201b and a steering wheel 201s. The operation unit 201 may include a switch for switching between manual operation and automatic operation of the own vehicle.

The travel control system 1 includes a travel control device 100 as a center, a state quantity detection device 10, an external environment recognition device 20, an acceleration/deceleration control device 30, a steering control device 40, an operation detection device 50, an alarm control device 60, and a map information output. The unit 70 and the own vehicle position detection device 80 are connected to each other via the information communication network 150 .

The state quantity detection device 10 includes a vehicle speed sensor, an acceleration sensor, an angular velocity sensor, a steering angle sensor, and the like, and detects state quantities such as vehicle speed, longitudinal acceleration, yaw rate, and steering angle of the own vehicle. At least some of the plurality of sensors included in the state quantity detection device 10 may share sensors attached to other devices included in the own vehicle. For example, the angular velocity sensor for detecting the yaw rate of the own vehicle, which is included in the state quantity detection device 10, may be shared with the angular velocity sensor included in the sideslip prevention device of the own vehicle.

The external environment recognition device 20 recognizes the shape of the road in front of the vehicle and the positions and shapes of objects existing around the vehicle based on information from a camera, sensor, or the like that recognizes the external environment of the vehicle. Output the recognition result. The external environment recognition device 20 includes, for example, a stereo camera that captures an image of the front of the vehicle, and recognizes the lane (driving lane) of the road on which the vehicle is running based on the image captured by the stereo camera. and the position and attitude of the host vehicle relative to the lane.

The acceleration/deceleration control device 30 is an electronic control device that controls the operation of the prime mover and the braking device provided in the host vehicle based on the operation of the operation unit 201 by the driver and instructions output from the travel control device 100, which will be described later. The acceleration/deceleration control device 30 controls acceleration, deceleration, starting and stopping of the host vehicle. In other words, the acceleration/deceleration control device 30 controls the longitudinal motion of the vehicle.

The prime mover of the own vehicle may be one or more internal combustion engines, one or more electric motors, or a combination thereof. Further, the braking device is not limited to one that converts the kinetic energy of the own vehicle into heat energy to generate braking force, and may be one that converts the kinetic energy of the own vehicle into electrical energy.

Note that the actual acceleration/deceleration control device 30 includes a plurality of electronic control devices, such as an electronic control device that controls the engine and an electronic control device that controls the braking device, and they cooperate with each other via the information communication network 150 and the like. It is realized by

The steering control device 40 is an electronic control device that controls the operation of the steering device of the host vehicle based on the operation of the operation unit 201 by the driver and the instructions output from the cruise control device 100, which will be described later. In addition to a device that applies a yaw moment to the vehicle by changing the steering angle, the steering device is a device that applies a yaw moment to the vehicle by generating a difference in braking force or driving force between the left and right wheels. may further include The steering control device 40 controls the yaw moment of the own vehicle generated by the operation of the steering device. In other words, the steering control device 40 controls the lateral movement of the vehicle.

The operation detection device 50 detects the operation of the operation unit 201 by the driver. The operation detection device 50 includes an accelerator pedal sensor 50a that detects operation of the accelerator pedal 201a, a brake pedal sensor 50b that detects operation of the brake pedal 201b, and a steering sensor 50s that detects operation of the steering wheel 201s. A part or all of the configuration of the operation detection device 50 may also serve as the configuration of the state quantity detection device 10 .

The accelerator pedal sensor 50a is a sensor that detects, for example, the amount of depression of the accelerator pedal 201a. Further, the brake pedal sensor 50b is a sensor that detects brake fluid pressure, for example. Also, the steering sensor 50s is, for example, a steering torque sensor that detects torque applied to the steering wheel 201s by the driver.

Note that the brake pedal sensor 50b may include a switch that detects the operation of the brake pedal 201b for controlling the lighting of the brake lamp of the own vehicle. Further, the steering sensor 50s may include a touch sensor provided on the steering wheel 201s.

The warning control device 60 is an electronic control device that controls a warning device that issues a warning to the driver. The notification device includes, for example, a display device that displays images and characters, a light emitting device that emits light, a speaker that emits sound, an actuator that emits vibration, or a combination thereof.

The map information output unit 70 stores and outputs map information indicating the shape of roads. The map information output unit 70 may store map information of a predetermined country or region prepared in advance, or may store map information stored in a server located outside the vehicle. The information may be received via road-to-vehicle communication, a mobile communication network, or the like according to the route that the host vehicle is scheduled to travel, and may be temporarily stored.

The map information stored by the map information output unit 70 includes lane data necessary for automatic driving of the own vehicle. The lane data includes, for example, lane center coordinates (latitude and longitude), lane width, lane azimuth angle, and the like.

The own vehicle position detection device 80 calculates current position information of the own vehicle using satellite navigation. Further, the own vehicle position detection device 80 calculates the current position information of the own vehicle on the map information based on the calculated current position information of the own vehicle and the map information stored in the map information output unit 70. Output. The current position information of the vehicle on the map information output by the vehicle position detection device 80 includes the shape of the lane in which the vehicle is traveling and the lateral direction (width direction) of the vehicle with respect to the center line of the lane. and the inclination (angle) of the own vehicle in the yaw direction with respect to the center line of the lane.

The lateral position of the vehicle with respect to the center line of the lane is determined by the distance and direction of lateral separation of the reference points fixed to the vehicle from the center line of the lane when the vehicle is viewed from directly above. expressed. In addition, the inclination of the vehicle in the yaw direction with respect to the center line of the lane is the distance between the axis passing through the reference point and parallel to the longitudinal direction of the vehicle and the center line of the lane when the vehicle is viewed from directly above. represented by the angle between

Hereinafter, the position of the host vehicle in the lateral direction with respect to the center line of the lane on the map information will be referred to as the to-lane lateral position Ex. Further, the inclination of the own vehicle in the yaw direction with respect to the center line of the lane on the map information is referred to as the lane-to-lane yaw angle Eθ. The values of the to-lane lateral position Ex and the to-lane yaw angle Eθ are used for steering control of the vehicle by the cruise control device 100 . For example, if Ex and Eθ are both zero, it means that the reference point fixed to the vehicle is located on the center line of the lane and the vehicle is running parallel to the center axis of the lane.

More specifically, vehicle position detection device 80 includes satellite navigation section 82 and vehicle position estimation section 85 . In addition, vehicle position detection device 80 includes a computer having a processor that executes a predetermined program.

The satellite navigation unit 82 generally performs positioning using a satellite positioning system called GNSS, GPS, or the like, and detects current position information of the own vehicle. Since the satellite positioning system is a well-known technology, detailed description is omitted. Note that the satellite navigation unit 82 may be configured to perform positioning using signals transmitted from ground-fixed facilities in addition to signals transmitted from satellites.

The satellite navigation unit 82 also calculates an estimated error value included in the positioning result and outputs it together with the positioning result. Below, the estimated value of the error included in the positioning result is referred to as positioning error. The positioning error includes at least horizontal positioning error information. A positioning error in the horizontal direction is represented, for example, as the radius of an error circle. The value of the positioning error changes according to changes in the number of satellites that can receive positioning signals, changes in the positions of the antenna of the satellite navigation unit 82 and each satellite, and the like.

The vehicle position estimation unit 85 matches the current position information of the vehicle detected by the satellite navigation unit 82 with the map information stored by the map information output unit 70 . Based on the current position information of the vehicle and the map information, the vehicle position estimator 85 calculates and outputs the shape of the lane in which the vehicle is traveling, the lateral position Ex and the yaw angle Eθ. . The details of the process of calculating the to-lane lateral position Ex by the vehicle position estimation unit 85 will be described later.

The vehicle position detection device 80 also has a configuration for performing autonomous navigation, but detailed description thereof will be omitted.

The travel control device 100 is an electronic control device that controls the acceleration/deceleration control device 30 and the steering control device 40, and performs travel control of the own vehicle. Based on information output from the state quantity detection device 10, the external environment recognition device 20, the map information output unit 70, the own vehicle position detection device 80, and the operation detection device 50, the travel control device 100 controls the acceleration/deceleration control device 30 and the steering operation. It controls the control device 40 .

The cruise control device 100 has a manual driving mode and a driving support mode, and selectively executes these modes to control the driving of the own vehicle. The manual driving mode is a driving mode in which the driver uses the operation unit 201 to control one or both of acceleration/deceleration and steering of the own vehicle. The driving support mode is a driving mode in which the cruise control device 100 executes part or all of the control of the acceleration/deceleration and steering of the host vehicle.

When the driving support mode is selected, the cruise control device 100 receives lane shape information detected by the external environment recognition device 20 and the own vehicle position detection device 80, information on the relative position and attitude of the own vehicle with respect to the lane, and Based on this, travel control of the host vehicle is automatically performed.

Next, the vehicle-to-lane lateral position calculation process executed by the vehicle position estimation unit 85 provided in the vehicle position detection device 80 will be described. FIG. 2 is a flowchart of the versus-lane lateral position calculation process. The own vehicle position estimator 85 repeatedly executes the to-lane lateral position calculation process shown in FIG. 2 at a predetermined cycle.

In the to-lane lateral position calculation process, first, in step S<b>10 , the vehicle position estimation unit 85 performs positioning using the satellite navigation unit 82 . By executing step S10, the vehicle position estimator 85 acquires the current position (latitude and longitude) and traveling direction of the vehicle. Also, in step S10, the obtained positioning result and the time when the positioning was executed are stored in the storage unit 85a.

Next, in step S20, the vehicle position estimating section 85 determines whether or not the positioning error by the satellite navigation section 82 is equal to or less than a predetermined threshold.

If it is determined in step S20 that the positioning error by the satellite navigation unit 82 is equal to or less than the predetermined threshold, the vehicle position estimation unit 85 proceeds to step S30. In step S30, the vehicle position estimating unit 85 directly obtains the current position and traveling direction of the vehicle acquired in step S10, and the lane data included in the map information stored in the map information output unit 70. compare. Then, based on the result of the comparison, the values of the to-lane lateral position Ex and the to-lane yaw angle Eθ are calculated.

Next, in step S40, the vehicle position estimation unit 85 temporarily stores the values of the to-lane lateral position Ex and the to-lane yaw angle Eθ calculated in step S30 in the storage unit 85a. Next, in step S50, the flag stored in the storage section 85a is set to 0.

The flag indicates whether or not the latest values of the to-lane lateral position Ex and the to-lane yaw angle Eθ stored in the storage unit 85a have been calculated by executing step S30. The value of the flag is 0 or 1. That is, when the flag is 0, the latest values of the to-lane lateral position Ex and the to-lane yaw angle Eθ are calculated by direct comparison between the positioning result of the satellite navigation unit 82 and the map information. When the flag is 1, the latest values of the to-lane lateral position Ex and the to-lane yaw angle Eθ are not calculated by direct comparison between the positioning results of the satellite navigation unit 82 and the map information.

In other words, when the flag is 0, the latest values of the to-lane lateral position Ex and the to-lane yaw angle Eθ are calculated in a state where the positioning error by the satellite navigation unit 82 is equal to or less than the predetermined threshold. Further, when the flag is 1, the latest values of the lateral position Ex and the yaw angle Eθ with respect to the lane are calculated in a state where the positioning error by the satellite navigation unit 82 exceeds the predetermined threshold value.

After executing step S50, the vehicle position estimator 85 ends the to-lane lateral position calculation process.

On the other hand, if the positioning error by the satellite navigation unit 82 exceeds the predetermined threshold in the determination of step S20, the vehicle position estimation unit 85 proceeds to step S100. In step S100, the vehicle position estimation unit 85 refers to the flag stored in the storage unit 85a and determines whether the flag value is zero.

That is, in step S100, the vehicle position estimation unit 85 determines whether or not the previous cross-lane lateral position calculation process was executed with the positioning error by the satellite navigation unit 82 being equal to or less than a predetermined threshold.

When it is determined in step S100 that the value of the flag is 0, the vehicle position estimator 85 proceeds to step S110. When it is determined in step S100 that the value of the flag is 1, the vehicle position estimation unit 85 skips step S110 and proceeds to step S120.

In step S110, the vehicle position estimation unit 85 stores the latest cross-lane lateral position Ex stored in the storage unit 85a in the storage unit 85a as the reference position Ex0. Also, in step S110, the vehicle position estimating section 85 stores the latest yaw angle EΘ stored in the storage section 85a in the storage section 85a as the reference yaw angle EΘ0. Further, in step S110, the vehicle position estimating unit 85 stores the time at which positioning for calculating the latest on-lane lateral position Ex stored in the storage unit 85a is stored in the storage unit 85a as the reference time T0. do.

In step S120, the vehicle position estimation unit 85 compares the latest positioning result by the satellite navigation unit 82 with the previous positioning result to determine the lateral direction of the vehicle during the period from the previous positioning to the current positioning. A relative movement amount ΔEx is calculated and stored in the storage unit 85a. ΔEx is hereinafter referred to as a relative lateral movement amount.

Next, in step S130, abnormal value determination processing is executed to determine whether or not the latest relative lateral movement amount ΔEx is an abnormal value. The method of abnormal value determination processing is not particularly limited. As an example in this embodiment, in the abnormal value determination process, the latest relative lateral movement amount ΔEx is the expected lateral movement amount when the host vehicle runs while maintaining the reference yaw angle EΘ0 from the reference time T0 to the present. is determined to be an abnormal value.

More specifically, in step S130, when the following equation holds, the vehicle position estimator 85 determines that the latest value of the relative lateral movement amount ΔEx is an abnormal value.
ΔEx>sin(Eθ0+0.2)・L
Here, L is the traveling distance of the own vehicle from the reference time T0 to the present.

When it is determined in step S130 that the latest relative lateral movement amount ΔEx is an abnormal value, the vehicle position estimator 85 replaces the latest relative lateral movement amount ΔEx with zero. Note that the abnormal value determination process in step S130 may be performed based on a comparison with the lateral movement amount of the vehicle calculated from the detection result of the gyro sensor provided in the vehicle, for example.

Next, in step S140, the vehicle position estimating section 85 integrates the relative lateral movement amount ΔEx from the reference time T0 to the present, and adds the result of the integration and the reference position Ex0 as the to-lane lateral position Ex. .

Next, in step S150, the vehicle position estimation unit 85 temporarily stores the value of the relative lateral movement amount ΔEx calculated in step S120 in the storage unit 85a. Next, in step S160, the flag stored in the storage unit 85a is set to 1. After executing step S160, the vehicle position estimator 85 ends the to-lane lateral position calculation process.

As described above, the vehicle position detection device 80 of the present embodiment directly compares the positioning result of the satellite navigation unit 82 with the map information during the period when the positioning error of the satellite navigation unit 82 is equal to or less than the predetermined threshold value. A to-lane lateral position Ex is calculated based on the result of the comparison.

In addition, the vehicle position detection device 80 of the present embodiment detects the relative lateral position of the vehicle obtained from the positioning result of the satellite navigation unit 80 during a period in which the positioning error of the satellite navigation unit 80 exceeds a predetermined threshold value. A to-lane lateral position Ex is calculated based on the result of integrating the movement amount ΔEx.

In general, when the number of satellites receiving signals in satellite navigation changes, the positioning error tends to increase and the positioning error tends to shift in one direction. In such a case, the vehicle position detection device 80 of the present embodiment stops using the result of direct comparison between the positioning result and the map information to calculate the to-lane lateral position Ex. Therefore, according to the vehicle position detection device 80 of the present embodiment, when the positioning error by the satellite navigation unit 82 increases, the vehicle-to-lane lateral position Ex calculated by the vehicle position detection device 80 does not correspond to the actual vehicle position. It is possible to prevent a large deviation from the position of the vehicle.

In addition, when the positioning error by the satellite navigation unit 82 becomes large, the own vehicle position detection device 80 of the present embodiment calculates the position of the vehicle from the continuous positioning results by the satellite navigation unit 82 after the positioning error has changed. A lateral position Ex relative to the lane is calculated by integrating the relative lateral movement amount of the vehicle. When the number of satellites receiving signals in satellite navigation changes, the positioning result shifts in one direction as described above, but the range of subsequent positioning result fluctuations often remains within a relatively small range. . Therefore, according to the vehicle position detection device 80 of the present embodiment, even after the positioning error by the satellite navigation unit 82 has increased, the actual behavior of the vehicle is relatively accurate to the value of the to-lane lateral position Ex. can be reflected in

As described above, the vehicle position detection device 80 of the present embodiment calculates the value of the lateral position Ex with high accuracy even if the magnitude of the error included in the positioning result of satellite navigation changes. be able to.

The present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the gist or idea of the invention that can be read from the scope of claims and the entire specification. A device is also included in the scope of the present invention.

1 cruise control system,
10 state quantity detection device,
20 external environment recognition device,
30 acceleration/deceleration control device,
40 steering control device,
50 operation detection device,
50a accelerator pedal sensor,
50b brake pedal sensor;
50s steering sensor,
60 alarm controller,
70 map information output unit,
80 own vehicle position detection device,
82 Satellite Navigation Department,
85 own vehicle position estimation unit,
85a storage unit,
100 travel control device,
150 information communication network,
201 operation unit,
201a accelerator pedal,
201b brake pedal,
201s steering wheel.

Claims (3)

It is installed in a vehicle equipped with a satellite navigation unit that performs positioning using a satellite positioning system and a map information output unit that outputs map information, and based on the positioning result of the satellite navigation unit and the map information, while the vehicle is running An own vehicle position detection device that calculates a lateral position relative to a lane that indicates the lateral position of the vehicle with respect to a center line of a certain lane,
During a period in which the positioning error of the satellite navigation unit is equal to or less than a predetermined threshold, the lateral position relative to the lane is calculated based on a direct comparison result between the positioning result of the satellite navigation unit and the map information,
During a period in which the positioning error of the satellite navigation unit exceeds a predetermined threshold, the lateral position to the lane last calculated with the positioning error being equal to or less than the predetermined threshold is used as a reference position, and at the reference position, A vehicle position detection device, wherein a result obtained by integrating relative lateral movement amounts of the vehicle obtained from positioning results by the satellite navigation unit is added to calculate the lateral position relative to the lane. The vehicle position detection device according to claim 1 , wherein the relative lateral movement amount is replaced with 0 when it is determined that the relative lateral movement amount is an abnormal value. . The amount of relative lateral movement is expected when the vehicle travels from the reference position to the current position while maintaining the lane-to-lane yaw angle, which is the yaw angle of the vehicle with respect to the centerline of the lane. If the amount of lateral movement is exceeded, the amount of relative lateral movement is determined to be the abnormal value.
3. The vehicle position detecting device according to claim 2, characterized in that:

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