JP7069624B2 - Position calculation method, vehicle control method and position calculation device - Google Patents

Description

The present invention relates to a position calculation method, a vehicle control method, and a position calculation device.

Conventionally, the navigation signal transmitted from the navigation satellite is received, the satellite positioning coordinates which are the coordinates determined based on the received navigation signal are calculated, the signal detected by the inertial sensor is acquired, and the movement amount of the moving body is sequentially calculated. Calculated, the position of the moving object is sequentially determined assuming that it has moved by the amount of movement from the virtual reference point, and the coordinates determined by multiplying the position of the moving object and the satellite positioning coordinates at the time of receiving the navigation signal by the weight coefficient are the virtual reference. A positioning method is known in which the virtual reference point is brought closer to the satellite positioning coordinates by using the coordinates of the points and increasing the weighting coefficient each time the position update process is executed.

International Publication 2016/203744

However, in the above-mentioned conventional positioning method, when the reception sensitivity of the satellite is deteriorated and the accuracy of the satellite is temporarily lowered, and then the reception sensitivity of the satellite is improved, the measured position becomes discontinuous. There is a problem that the change in the calculated position value is large.

An object to be solved by the present invention is to provide a position calculation method or a position calculation device that suppresses a change in a position calculation value.

The present invention calculates the position of the own vehicle as the own vehicle position based on the detection value of the sensor and the satellite signal, and calculates the allowable change amount of the own vehicle position according to the allowable range of the movement of the own vehicle in the travel control device . The above is performed by comparing the allowable change amount and the change amount of the own vehicle position, executing a correction process for limiting the change in the own vehicle position according to the comparison result, and outputting the own vehicle position after the correction process. Solve the problem.

The present invention can suppress changes in the calculated value of the position.

It is a block diagram of the vehicle control system of the vehicle which concerns on this embodiment. It is a functional block diagram of the vehicle control system shown in FIG. It is a flowchart which shows the control flow of the vehicle control system shown in FIG.

Hereinafter, a vehicle control system for a vehicle according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, the present invention will be described by exemplifying a travel control device mounted on a vehicle.

FIG. 1 is a diagram showing a configuration of a vehicle control system for a vehicle according to an embodiment of the present invention. As shown in FIG. 1, the vehicle control system according to the present embodiment includes a position calculation device 10, a vehicle control device 20, and a drive mechanism 30. The position calculation device 10 calculates the current position of the own vehicle by using the GPS system and the sensor that detects the state of the own vehicle. The vehicle control device 20 calculates the travel route of the own vehicle using the map data, acquires the current position of the own vehicle from the position calculation device 10, and controls the drive mechanism 30 so that the own vehicle travels on the travel route. By doing so, the running of the own vehicle is controlled.

The position calculation device 10 includes a receiver 11, a yaw rate sensor 12, an acceleration sensor 13, and a calculation device 14. These devices are connected by a CAN (Controller Area Network) or other in-vehicle LAN in order to exchange information with each other.

The receiver 11 receives radio waves transmitted from a plurality of satellite communications. The receiver 11 is a receiving device included in the GPS unit. The receiver 11 demodulates the signal transmitted from the GPS radio wave and outputs the satellite positioning signal (satellite signal) to the arithmetic unit 14. The yaw rate sensor 12 is provided on the own vehicle and detects the yaw rate (change speed of the rotation angle in the turning direction) of the own vehicle. The acceleration sensor 13 is a sensor that detects the acceleration of the own vehicle. A gyro sensor or the like is used for the acceleration sensor 13.

The arithmetic unit 14 has a ROM (Read Only Memory) containing a program for calculating the current position of the own vehicle and correcting the current position, and a processor (CPU: Central Processing Unit) for executing the program stored in the ROM. ) And a RAM (Random Access Memory) that functions as an accessible storage device. The arithmetic unit 14 outputs the calculated own vehicle position to the vehicle control device 20.

The vehicle control device 20 calculates a travel route, and controls the travel of the own vehicle so that the own vehicle travels on the travel route based on the own vehicle position calculated by the position calculation device 10. When the preceding vehicle is in front of the own vehicle, the vehicle control device 20 maintains the inter-vehicle distance between the own vehicle and the preceding vehicle at the inter-vehicle distance set by the driver so that the own vehicle follows the preceding vehicle. , Control your vehicle. When the preceding vehicle does not exist in front of the own vehicle, the speed control for driving the own vehicle at the vehicle speed set by the driver is performed. The vehicle control (automatic driving control) by the vehicle control device 20 is not limited to the control that does not require driver intervention, but may be a control that partially requires driver intervention. The vehicle control device 20 includes a camera 21, a map database 22, and a control device 23.

The camera 21 is installed in front of and / or behind the own vehicle, and images the roads and objects around the own vehicle. The map database 22 records map information. In the map information, information on the road shape at each map coordinate, for example, attributes related to curves, slopes, intersections, interchanges, narrow roads, straight roads, shoulder structures, and confluence points is recorded in association with the map coordinates.

The control device 23 includes a ROM containing a program for calculating the travel route of the own vehicle and executing automatic driving control, a processor (CPU: Central Processing Unit) for executing the program stored in the ROM, and a RAM. (Random Access Memory) etc. These devices are connected by a CAN (Controller Area Network) or other in-vehicle LAN in order to exchange information with each other. The control device 23 calculates a control command value for automatically driving the own vehicle, and outputs the control command value to the drive mechanism 30.

The drive mechanism 30 includes an engine and / or a motor (power system), a brake (braking system), a steering actuator (steering system), and the like. In the present embodiment, the operation of the drive mechanism 30 is controlled by the control device 23 when the automatic traveling control described later is performed.

Next, with reference to FIG. 2, the arithmetic processing by the position arithmetic unit 10 and the control processing by the vehicle control apparatus 20 will be described. FIG. 2 is a block diagram showing functional blocks included in the arithmetic unit 10 and the control device 23, respectively.

The arithmetic unit 14 of the position arithmetic unit 10 has a vehicle position calculation unit 141, a permissible change amount calculation unit 142, and a correction processing unit 143 as functional blocks for executing arithmetic processing. The control device 23 of the vehicle control device 20 has a travel route calculation unit 231 and a travel control unit 232 as functional blocks for executing the travel control process of the own vehicle.

The arithmetic processing of the position arithmetic unit 10 will be described. The arithmetic unit 14 calculates the vehicle position based on the satellite signal received by the receiver 11 and the detection values of various sensors such as the yaw rate sensor 12 in the vehicle position calculation unit 141. The arithmetic unit 14 acquires the position coordinates and the transmission time of the satellite signal from the satellite signal, respectively, and acquires the state quantity of the vehicle from the detection values of various sensors and the vehicle speed information. The state quantity of the vehicle is a value representing the current running state of the vehicle, and is represented by the vehicle speed, acceleration, yaw rate, or the like. The vehicle speed information includes the traveling speed of the own vehicle. A vehicle speed sensor is provided in a drive system such as a drive shaft, and the vehicle speed sensor outputs a wheel speed pulse signal. Then, the vehicle speed is calculated from the pulse interval of the wheel speed pulse signal. The yaw rate and acceleration are detected by the inertial sensor (yaw rate sensor 12 and acceleration sensor 13).

The own vehicle position calculation unit 141 calculates the radio wave propagation time from each time indicated by the satellite signals transmitted from the plurality of satellites, multiplies the radio wave propagation time by the speed of light, and each of the receiver 11 to the plurality of satellites. Measure the distance. The own vehicle position calculation unit 141 calculates the intersection of each measured distance as the own vehicle position for satellite positioning.

The own vehicle position calculation unit 141 calculates the own vehicle position by integrating inertial navigation with the above satellite positioning in order to improve the calculation accuracy of the own vehicle position. The own vehicle position calculation unit 141 executes arithmetic processing such as an extended Kalman filter for the own vehicle position and the vehicle state quantity measured by satellite positioning. The vehicle position calculated by satellite positioning is a discrete value in a time series calculated in a predetermined cycle. Since the calculated value calculated by satellite positioning includes an error, the own vehicle position calculation unit 141 performs an calculation process for reducing the error by using a filtering process. The filtering process predicts the next own vehicle position from the comparison result while comparing the previous calculated value and the current calculated value with respect to the calculated value acquired in the time series. The own vehicle position calculation unit 141 uses the state quantity of the vehicle for predicting the own vehicle position. The own vehicle position calculation unit 141 repeatedly executes the filtering process using the Kalman filter to estimate (specific calculation) the optimum state quantity for the own vehicle position measured by satellite positioning. The own vehicle position calculation unit 141 calculates the estimated optimum state quantity as the own vehicle position and outputs it to the correction processing unit 143. The calculation process of the own vehicle position by the own vehicle position calculation unit 141 is not limited to the estimation method using the Kalman filter, and may be another known calculation method.

The arithmetic unit 14 calculates the permissible change amount in the permissible change amount calculation unit 142 based on the vehicle state amount. The permissible amount of change indicates the upper limit of the amount of change in the position of the own vehicle. In the calculation of the own vehicle position by satellite positioning, if the reception sensitivity of the satellite deteriorates due to underpass (when passing under the overpass) or multipath, the calculated value by the own vehicle position calculation unit 141 becomes discontinuous. , When viewed in chronological order, the amount of change in the calculated value becomes large. Then, in the vehicle running control described later, when the vehicle is controlled based on the position of the own vehicle having a large amount of change, the behavior of the vehicle may change suddenly. Therefore, in the present embodiment, the allowable change amount is calculated, the upper limit is set for the change of the own vehicle position, and the change amount of the own vehicle position is limited.

The permissible amount of change is a value expressing the permissible range of the movement (behavior) of the vehicle by the amount of change in the position of the own vehicle. The permissible amount of change is set according to the permissible range of movement of the own vehicle. For example, in executing the automatic driving control, the permissible range of the movement of the vehicle is determined in advance by the limit value of the vehicle state amount so that the occupant feels uncomfortable with the change in the state of the vehicle. For example, it is determined in advance by an experiment or a simulation whether or not the occupant feels uncomfortable with the speed change (acceleration) in the automatic driving control. The amount of change in the position of the own vehicle corresponding to the determined amount of vehicle condition is set as the allowable amount of change. The limit value of the vehicle state amount (allowable range of vehicle movement) is expressed by, for example, the lateral acceleration of the vehicle. The lateral acceleration is the acceleration of the own vehicle (acceleration of the lateral component of the own vehicle) in the direction perpendicular to the traveling direction of the own vehicle. The lower limit of the lateral acceleration limit is set to -0.05G, and the upper limit of the lateral acceleration limit is set to + 0.05G.

The permissible change amount calculation unit 142 calculates the permissible change amount using the following equations (1) to (6). First, the permissible change amount calculation unit 142 acquires the vehicle speed from the vehicle speed information, and calculates the permissible steering amount (δ) using the equation (1).

However, in equation (1), g indicates the gravitational acceleration, l indicates the wheelbase, m indicates the vehicle weight, V ₀ indicates the current vehicle speed, and l _f indicates the distance from the vehicle center of gravity to the front axle. , L _g indicates the distance from the center of gravity of the vehicle to the rear axle, K _f indicates the cornering power of the front wheel tire, and _Kr indicates the cornering power of the rear wheel tire.

The permissible change amount calculation unit 142 uses the calculation result (δ) of the formula (1), and the permissible yaw rate (γ) and the permissible vehicle body slip angle (β) according to the formulas (2) and (3). Is calculated.

The permissible change amount calculation unit 142 calculates the permissible change amount by the formulas (4) to (6) using the calculation results (γ, β) of the formula (2) and the formula (3).

However, X indicates the lateral position coordinates of the own vehicle, Y indicates the position coordinates in the traveling direction (vertical direction) of the own vehicle, and θ is the azimuth angle with respect to the X axis of the own vehicle. X ₀ and Y ₀ indicate the position coordinates of the current vehicle position, and θ ₀ is the current azimuth angle. Note that t is an arbitrary time, and may be, for example, a sampling time.

The permissible change amount calculation unit 142 calculates the value of the second term included in the equations (4) to (6) as the permissible change amount and outputs it to the correction processing unit 143.

The arithmetic unit 14 calculates the amount of change in the position of the own vehicle in the correction processing unit 143, compares the allowable change amount with the amount of change in the position of the own vehicle, and corrects the change in the position of the own vehicle according to the comparison result. do.

The correction processing unit 143 calculates the amount of change in the own vehicle position by calculating the difference between the previous value and the current value of the own vehicle position calculated by the own vehicle position calculation unit 141. The vehicle position is represented by the position coordinates (X, Y) and the azimuth angle (θ). The correction processing unit 143 calculates a change amount for each of a plurality of indexes (position coordinates, azimuth angle) indicating the position of the own vehicle, and compares them with the allowable change amount (X, Y, θ). When the amount of change is equal to or less than the allowable change amount, the correction processing unit 143 does not correct the calculated value of the own vehicle position calculation unit 14, and the output value of the own vehicle position calculation unit 141 is finally used as the position calculation device 10. It is output to the vehicle control device 20 as an output calculation value. The output calculation value is a calculation value of the own vehicle position output from the position calculation device 10 to the vehicle control device 20.

When the amount of change is larger than the allowable change amount, the correction processing unit 143 limits the change in the vehicle position so that the change amount becomes the allowable change amount (allowable upper limit value), and corrects the vehicle position. .. Then, the correction processing unit 143 outputs the calculated value of the own vehicle position after the correction to the vehicle control device 20 as the final output calculation value of the position calculation device 10. As a result, the correction processing unit 143 performs correction processing on the calculated value of the own vehicle position so that the change in the own vehicle position is equal to or less than the allowable change amount.

The control process of the vehicle control device 20 will be described. The control device 23 calculates the travel route of the own vehicle in the travel route calculation unit 231. The travel route calculation unit 231 calculates the travel route of the own vehicle using the destination information and the map information. The destination is input by the driver or the user. The map information is stored in the map database 22. The travel route represents the lane in which the own vehicle should travel. The travel route calculation unit 231 outputs the calculated travel route to the travel control unit 232.

The travel control unit 232 detects the position of the preceding vehicle using the camera image. The travel control unit 23 acquires the current position of the own vehicle from the position calculation device 10. The travel control unit 23 calculates a control command value for executing speed control and steering control so that the own vehicle travels on the travel route while following the own vehicle at a predetermined distance from the preceding vehicle. .. The control command value is represented by an accelerator opening degree, a brake operation amount, a steering actuator operation amount, and the like. The travel control unit 23 outputs the calculated control command value to the drive mechanism 30.

Next, the control flow of the vehicle control system will be described with reference to the flowchart shown in FIG. In FIG. 3, the control flow of steps 1 to 9 shows the control flow executed by the position calculation device 10, and the control flow of step S10 shows the control flow executed by the vehicle control device 20. The control flow of steps 1 to 10 is repeatedly executed at a predetermined cycle during the execution of the automatic operation control.

In step 1, the receiver 11 receives the satellite signal. In step 2, the arithmetic unit 14 acquires vehicle speed information. In step 3, the arithmetic unit 14 acquires the vehicle state quantity from various sensors such as the yaw rate sensor 12. In step 4, the arithmetic unit 14 calculates the position of the own vehicle based on the satellite signal and the detection value of the sensor. Specifically, the own vehicle position calculation unit 141 calculates the own vehicle position by integrating the measurement method by satellite positioning (position measurement method using an external signal) and the inertial navigation system.

In step 5, the arithmetic unit 14 calculates the allowable change amount based on the vehicle state quantity. In step 6, the arithmetic unit 14 calculates the amount of change in the own vehicle position by taking the difference between the previous own vehicle position and the current own vehicle position. In step 7, the arithmetic unit 14 compares the change amount of the own vehicle position with the allowable change amount, and determines whether or not the change amount of the own vehicle position is equal to or less than the allowable change amount.

When it is determined that the change amount of the own vehicle position is equal to or less than the allowable change amount, the arithmetic unit 14 calculates the calculated value of the own vehicle position by integrating satellite positioning and inertial navigation in step 8. , It is output to the vehicle control device 20 as an output calculation value. When it is determined that the change amount of the own vehicle position is larger than the allowable change amount, the arithmetic unit 14 self-determines in step 9 so that the change amount of the own vehicle position becomes the allowable change amount (allowable upper limit value). The calculated value of the vehicle position is corrected, and the calculated value after the correction processing is output to the vehicle control device 20 as an output calculated value.

In step 10, the control device 23 of the vehicle control device 20 calculates a control command value based on the calculated value of the own vehicle position and the traveling path output from the vehicle control device 20, and outputs the control command value to the drive mechanism 30. As a result, vehicle running control (automatic driving control) of the own vehicle is executed.

As described above, in the present embodiment, the position of the own vehicle is calculated as the own vehicle position based on the detection value of the sensor and the satellite signal, and the allowable change amount of the own vehicle position set according to the allowable range of the movement of the own vehicle. Is compared with the amount of change in the position of the own vehicle, a correction process for limiting the change in the position of the own vehicle is executed according to the comparison result, and the position of the own vehicle after the correction process is output. As a result, it is possible to suppress changes in the position of the own vehicle in a situation where the positioning condition of the satellite is poor.

Further, in the present embodiment, the allowable change amount is calculated based on the state of the own vehicle, and when the change amount of the own vehicle position is larger than the allowable change amount, the change is limited to the own vehicle position. Executes the correction process of. As a result, the change in the position of the own vehicle can be suppressed so that the amount of change in the position of the own vehicle is within the allowable change amount.

Further, in the present embodiment, the allowable change amount is calculated based on the upper limit value of the change amount of the lateral acceleration. As a result, it is possible to suppress the change in the position of the own vehicle so that the change in the lateral acceleration of the position of the own vehicle is within the permissible value.

Further, in the present embodiment, the permissible amount of change is set by the permissible value of the position change in the plane coordinate system and the permissible value of the change of the yaw rate of the own vehicle. As a result, in addition to the position change of the plane coordinate system of the own vehicle position, the change of the yaw rate can be suppressed.

Further, in the present embodiment, the travel route of the own vehicle is calculated using the map data, and the travel of the vehicle is controlled so that the own vehicle travels on the travel route based on the correction processing of the own vehicle position and the travel route. .. As a result, sudden changes in vehicle behavior due to changes in the position of the own vehicle can be suppressed, and stable driving control can be realized in various driving environments.

Further, in the present embodiment, when the amount of change in the position of the own vehicle is equal to or less than the allowable change amount, the own vehicle is driven on the travel route based on the position of the own vehicle and the travel route before the correction process. Control driving. As a result, when the change in the position of the own vehicle is within the allowable range, the calculated value of the position of the own vehicle used for the vehicle traveling control can be returned to the true value.

As the position calculation method or the position calculation device 10 according to the modification of the present embodiment, the permissible change amount calculation unit 142 may calculate the permissible change amount based on the traveling locus. The travel locus corresponds to a target locus for the own vehicle to travel when the automatic driving control is executed. The vehicle control device 20 calculates a target locus of its own vehicle by using a vehicle locus prediction model when performing automatic control control. The vehicle control device 20 calculates a target locus on which the own vehicle should travel by using a travel route, map information, and a camera image.

The permissible change amount calculation unit 142 calculates the amount of change in the position allowed with respect to the calculated target locus as the permissible change amount. The permissible amount of change is set according to the shape of the road on the travel route. For example, when a vehicle turns right at an intersection, lateral behavior of the vehicle is allowed to some extent. On the other hand, when the vehicle is traveling on a straight road and the lateral change of the vehicle is large, the occupant feels uncomfortable. Therefore, the permissible change amount calculation unit 142 reduces the permissible change amount when the target locus is a straight line, and increases the permissible change amount when the target locus is a right / left turn or a curved line. As a result, in the modified example, it is possible to suppress a sudden change in the position of the own vehicle and also suppress a change in the posture of the vehicle.

10 ... Position calculation device 11 ... Receiver 12 ... Yaw rate sensor 13 ... Acceleration sensor 14 ... Calculation device 20 ... Vehicle control device 21 ... Camera 22 ... Map database 23 ... Control device 30 ... Drive mechanism 141 ... Own vehicle position calculation unit 142 ... Allowable change amount calculation unit 143 ... Correction processing unit 231 ... Travel route calculation unit 232 ... Travel control unit

Claims (8)

Receive satellite signal,
Using a sensor, detect the state of your vehicle and
Based on the satellite signal and the detection value detected by the sensor, the position of the own vehicle is calculated as the own vehicle position.
It is a position calculation method that outputs the own vehicle position to a traveling control device that controls the traveling of the own vehicle so that the own vehicle travels on the traveling path based on the own vehicle position.
Calculate the amount of change in the position of the own vehicle,
Based on the detection value detected by the sensor, the permissible change amount of the own vehicle position is calculated according to the permissible range of the movement of the own vehicle in the travel control device.

The allowable change amount and the change amount of the own vehicle position are compared, and a correction process for limiting the change of the own vehicle position is executed according to the comparison result.
A position calculation method for outputting the position of the own vehicle after the correction process. The position calculation method according to claim 1.
The permissible change amount is calculated based on the state of the own vehicle, and the allowable change amount is calculated.
A position calculation method for limiting a change in the position of the own vehicle when the amount of change in the position of the own vehicle is larger than the allowable change amount in the correction process. The position calculation method according to claim 2.
The permissible change amount is calculated based on the upper limit value of the change amount of the lateral acceleration.
The lateral acceleration is a position calculation method indicating the acceleration of the own vehicle in a direction perpendicular to the traveling direction of the own vehicle. The position calculation method according to claim 2 or 3.
Calculate the traveling locus of the own vehicle and calculate
A position calculation method for calculating the allowable change amount based on the travel locus. In the position calculation method according to any one of claims 1 to 4,
The permissible change amount is a position calculation method set by the permissible value of the position change in the plane coordinate system and the permissible value of the change of the yaw rate of the own vehicle. In the vehicle control method for controlling a vehicle based on the own vehicle position calculated by the position calculation method according to any one of claims 1 to 5.
Using the map data, the travel route of the own vehicle is calculated, and
A vehicle control method for controlling the traveling of the own vehicle so that the own vehicle travels on the traveling route based on the own vehicle position and the traveling route after the correction processing. In the vehicle control method according to claim 6,
When the amount of change in the position of the own vehicle is equal to or less than the allowable change amount, the own vehicle is driven on the travel route based on the position of the own vehicle and the travel route before the correction process. A vehicle control method that controls the running of a vehicle. A communication device that receives satellite signals and
A sensor that detects the state of your vehicle and
Based on the satellite signal and the detection value detected by the sensor, the position of the own vehicle is calculated as the own vehicle position, and the own vehicle travels so that the own vehicle travels on the travel path based on the own vehicle position. The travel control device that controls the vehicle is equipped with a controller that outputs the vehicle position .
The controller
Calculate the amount of change in the position of the own vehicle,
Based on the detection value detected by the sensor, the permissible change amount of the own vehicle position is calculated according to the permissible range of the movement of the own vehicle in the travel control device.
The allowable change amount and the change amount of the own vehicle position are compared, and a correction process for limiting the change of the own vehicle position is executed according to the comparison result.
A position calculation device that outputs the position of the own vehicle after the correction process.

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