JP7586010B2 - Course estimation device and course estimation program - Google Patents

Description

The present invention relates to a path estimation device and a path estimation program that estimate the path of a vehicle.

The device described in Patent Document 1 is known as a device that predicts the vehicle's course based on yaw rate and steering angle. This device predicts the vehicle's course based on the measurement results of yaw rate or steering angle that have been subjected to low-pass filtering, and the measurement results of vehicle speed.

However, in predicting a course based on yaw rate, etc., the yaw rate, etc. may fluctuate momentarily and significantly due to steering wheel wobble, noise, etc. If such fluctuations are directly reflected in the course prediction, the accuracy of the course prediction will decrease, and appropriate driving assistance will not be possible.

For this reason, the device described in Patent Document 1 is configured to apply low-pass filter processing to measured values such as yaw rate, thereby suppressing the effects of sudden fluctuations in yaw rate, etc., and enabling the vehicle to accurately predict the vehicle's course even if the vehicle's steering wheel wobbles. Furthermore, when the vehicle's planned road ahead is curved, the device improves the accuracy of the course prediction by lowering the time constant of the low-pass filter processing. On the other hand, when the vehicle's planned road is a straight road, the device increases the time constant to prevent the accuracy of the course prediction from being reduced by the effects of fluctuations in yaw rate, etc., caused by steering wheel wobbles, etc.

JP 2014-191596 A

Even in the device described in Patent Document 1, which changes the time constant of the low-pass filter processing according to the driving environment, such as the curvature of the road on which the vehicle is scheduled to travel, there is still room for improvement. Specifically, for example, in a situation where the driver is beginning to perform steering behavior, particularly in a situation where the driver may suddenly steer (for example, in a parking lot), it may be difficult to accurately judge the driving environment. The present invention has been made in consideration of the circumstances exemplified above. That is, the present invention provides a technology that can, for example, improve the accuracy of estimating the vehicle's course more accurately than before.

The course estimation device (4) according to the first aspect is configured to be mounted on a host vehicle (C) to estimate a course of the host vehicle.
This route estimation device is
A measurement result acquisition unit (402) that acquires a measured state quantity that is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
A filter (403) that performs low-pass filtering on the periodic measurement results of the state quantity;
a characteristic setting unit (404) for setting a filter characteristic, which is a response characteristic of the filter, in response to the measured state quantity or a change in the measured state quantity;
an estimated path calculation unit (405) that calculates an estimated path of the host vehicle based on an estimated state quantity that is an output of the filter;
Equipped with
The characteristic setting unit sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the duration of a change in the same direction in the measured state quantity is less than a predetermined time, is on the low-response side corresponding to a larger time constant than a second filter characteristic, which is the filter characteristic when the duration is equal to or longer than the predetermined time.
The course estimation device (4) according to the third aspect is configured to be mounted on a host vehicle (C) to estimate the course of the host vehicle.
This route estimation device is
A measurement result acquisition unit (402) that acquires a measured state quantity that is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
A filter (403) that performs low-pass filtering on the periodic measurement results of the state quantity;
a characteristic setting unit (404) for setting a filter characteristic, which is a response characteristic of the filter, in response to the measured state quantity or a change in the measured state quantity;
an estimated path calculation unit (405) that calculates an estimated path of the host vehicle based on an estimated state quantity that is an output of the filter;
Equipped with
The characteristic setting unit sets the filter characteristics such that, in a first case and a second case in which the amount of change or the rate of change of the measured state quantity is different, a first filter characteristic, which is the filter characteristic in the first case in which the amount of change or the rate of change is smaller than that in the second case, is on the high response side corresponding to a smaller time constant than a second filter characteristic, which is the filter characteristic in the second case.
The course estimation device (4) according to the fifth aspect is configured to be mounted on a host vehicle (C) to estimate the course of the host vehicle.
This course estimation device
A measurement result acquisition unit (402) that acquires a measured state quantity that is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
A filter (403) that performs low-pass filtering on the periodic measurement results of the state quantity;
a characteristic setting unit (404) for setting a filter characteristic, which is a response characteristic of the filter, in response to the measured state quantity or a change in the measured state quantity;
an estimated path calculation unit (405) that calculates an estimated path of the host vehicle based on an estimated state quantity that is an output of the filter;
Equipped with
The characteristic setting unit sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the measured state quantity is less than a predetermined value, is on the high response side corresponding to a smaller time constant than a second filter characteristic, which is the filter characteristic when the measured state quantity is equal to or greater than the predetermined value.
The course estimation device (4) according to the seventh aspect is configured to be mounted on a host vehicle (C) to estimate the course of the host vehicle.
This course estimation device
A measurement result acquisition unit (402) that acquires a measured state quantity that is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
A filter (403) that performs low-pass filtering on the periodic measurement results of the state quantity;
a characteristic setting unit (404) for setting a filter characteristic, which is a response characteristic of the filter, in response to the measured state quantity or a change in the measured state quantity;
an estimated path calculation unit (405) that calculates an estimated path of the host vehicle based on an estimated state quantity that is an output of the filter;
Equipped with
The characteristic setting unit sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the polarity of the measured state quantity and the direction of change of the measured state quantity are opposite, is on the low-response side corresponding to a larger time constant than a second filter characteristic, which is the filter characteristic when the polarity and the direction of change of the measured state quantity are the same.
The course estimation program according to claim 10 is a program that can be stored in a computer-readable non-transient tangible storage medium and is executed by a course estimation device (4) that is configured to be mounted on a vehicle (C) to estimate a course of the vehicle, the program comprising:
The process executed by the course estimation device is
A measurement result acquisition process for acquiring a measured state quantity which is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
a low-pass filter process for the periodic measurement results of the state quantity;
A characteristic setting process for setting a filter characteristic, which is a response characteristic in the low-pass filter process, in response to the measured state quantity or a change state of the measured state quantity;
an estimated path calculation process for calculating an estimated path of the host vehicle based on an estimated state quantity that is an output of the low-pass filter process;
Including,
The characteristic setting process sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the duration of a change in the same direction in the measured state quantity is less than a predetermined time, is on the low-response side corresponding to a larger time constant than a second filter characteristic, which is the filter characteristic when the duration is equal to or longer than the predetermined time.
The course estimation program according to claim 12 is a program that can be stored in a computer-readable non-transient tangible storage medium and is executed by a course estimation device (4) that is configured to be mounted on a vehicle (C) to estimate a course of the vehicle, the program comprising:
The process executed by the course estimation device is
A measurement result acquisition process for acquiring a measured state quantity which is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
a low-pass filter process for the periodic measurement results of the state quantity;
A characteristic setting process for setting a filter characteristic, which is a response characteristic in the low-pass filter process, in response to the measured state quantity or a change state of the measured state quantity;
an estimated path calculation process for calculating an estimated path of the host vehicle based on an estimated state quantity that is an output of the low-pass filter process;
Including,
The characteristic setting process sets the filter characteristics such that, in a first case and a second case in which the amount of change or the rate of change of the measured state quantity is different, a first filter characteristic, which is the filter characteristic in the first case in which the amount of change or the rate of change is smaller than that in the second case, is on the high response side corresponding to a smaller time constant than a second filter characteristic, which is the filter characteristic in the second case.
The course estimation program according to claim 14 is a program that can be stored in a computer-readable non-transient tangible storage medium and is executed by a course estimation device (4) that is configured to be mounted on a vehicle (C) to estimate a course of the vehicle, the program comprising:
The process executed by the course estimation device is
A measurement result acquisition process for acquiring a measured state quantity which is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
a low-pass filter process for the periodic measurement results of the state quantity;
A characteristic setting process for setting a filter characteristic, which is a response characteristic in the low-pass filter process, in response to the measured state quantity or a change state of the measured state quantity;
an estimated path calculation process for calculating an estimated path of the host vehicle based on an estimated state quantity that is an output of the low-pass filter process;
Including,
The characteristic setting process sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the measured state quantity is less than a predetermined value, is on the high response side corresponding to a smaller time constant than a second filter characteristic, which is the filter characteristic when the measured state quantity is equal to or greater than the predetermined value.
The course estimation program according to claim 16 is a program that can be stored in a computer-readable non-transient tangible storage medium and is executed by a course estimation device (4) that is configured to be mounted on a vehicle (C) to estimate a course of the vehicle, the program comprising:
The process executed by the course estimation device is
A measurement result acquisition process for acquiring a measured state quantity which is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
a low-pass filter process for the periodic measurement results of the state quantity;
A characteristic setting process for setting a filter characteristic, which is a response characteristic in the low-pass filter process, in response to the measured state quantity or a change state of the measured state quantity;
an estimated path calculation process for calculating an estimated path of the host vehicle based on an estimated state quantity that is an output of the low-pass filter process;
Including,
The characteristic setting process sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the polarity of the measured state quantity and the direction of change of the measured state quantity are opposite, is on the low-response side corresponding to a larger time constant than a second filter characteristic, which is the filter characteristic when the polarity and the direction of change of the measured state quantity are the same.

In addition, in each section of the application documents, each element may be given a reference symbol in parentheses. However, such a reference symbol merely indicates an example of the correspondence between the element and the specific means described in the embodiment described below. Therefore, the present invention is not limited in any way by the description of the above reference symbols.

1 is a plan view showing a schematic configuration of a host vehicle equipped with an in-vehicle system including an electronic control device corresponding to a course estimation device according to an embodiment. 2 is a block diagram showing a schematic configuration of the in-vehicle system shown in FIG. 1 . 3 is a block diagram showing a schematic functional configuration realized by the electronic control device shown in FIG. 2. 3 is a time chart showing an outline of the operation of the electronic control device shown in FIG. 2 . 3 is a flowchart showing an outline of the operation of the electronic control device shown in FIG. 2 .

(Embodiment)
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that various modified examples applicable to one embodiment may be hindered from understanding the embodiment if they are inserted in the middle of a series of explanations related to the embodiment. For this reason, the modified examples are described together after the explanation of the embodiment.

(In-vehicle system configuration)
1, the in-vehicle system 1 is mounted on a vehicle C as a moving body. The vehicle C is a so-called four-wheeled automobile, and has a box-shaped body C1 formed in a substantially rectangular shape in a plan view. The shape of each part of the vehicle C in a "plan view" refers to the shape of that part when the vehicle C is stably placed on a horizontal surface so as to be able to run, and the part is viewed from the line of sight in the same direction as the direction of gravity. The vehicle C equipped with the in-vehicle system 1 according to this embodiment is hereinafter referred to as "host vehicle C."

Hereinafter, the imaginary straight line that passes through the center of the host vehicle C in the vehicle width direction in a plan view and is parallel to the vehicle overall length direction of the host vehicle C is referred to as the vehicle width center line CL. The vehicle width center line CL may also be referred to as the vehicle center line. The vehicle overall length direction is a direction perpendicular to the vehicle width direction and perpendicular to the vehicle height direction. The vehicle height direction is a direction that determines the height of the host vehicle C, and is a direction parallel to the direction of gravity when the host vehicle C is stably placed on a horizontal surface so that it can run. In addition, "front," "rear," "left," "right," and "up" are defined as shown by the arrows in Figure 1. In other words, the vehicle overall length direction is synonymous with the front-rear direction. In addition, the vehicle width direction is synonymous with the left-right direction.

The in-vehicle system 1 is configured as a driving assistance system that detects an obstacle D around the vehicle C and avoids a collision by steering control and/or braking control when there is a possibility of a collision with the detected obstacle D. Specifically, the in-vehicle system 1 is configured to calculate an estimated path P of the vehicle C and to execute motion control of the vehicle C to avoid a collision based on the estimated path P and the detection result of the obstacle D.

Referring to FIG. 2, the in-vehicle system 1 includes a vehicle condition sensor 2, a driving environment sensor 3, an electronic control device 4, an alarm 5, and a vehicle control unit 6.

The vehicle state sensor 2 is provided to generate outputs corresponding to quantities related to the driving state of the vehicle C. The "various quantities related to the driving state" include, for example, quantities related to the driving operation state by the driver or the driving automation system, such as the accelerator operation amount, the brake operation amount, the shift position, and the steering angle. The "various quantities related to the driving state" also include physical quantities related to the behavior of the vehicle C, such as the vehicle speed, the angular velocity, the forward/rearward acceleration, and the left/right acceleration. In other words, the vehicle state sensor 2 is a collective term for well-known sensors necessary for vehicle driving control, such as an accelerator opening sensor, a steering angle sensor, a wheel speed sensor, an angular velocity sensor, an acceleration sensor, and a yaw rate sensor, for the sake of simplicity of illustration and explanation. The vehicle state sensor 2 is provided so as to be able to provide a detection output to the electronic control unit 4 via an in-vehicle communication line.

The driving environment sensor 3 is provided to detect the driving environment of the vehicle C other than the weather (i.e., outside temperature, illuminance, etc.). Specifically, the driving environment sensor 3 is configured to detect moving and stationary objects within a predetermined detection range around the vehicle C. "Moving objects" include pedestrians, cyclists, animals, and other vehicles that are in operation. "Stationary objects" include objects that have fallen on the road, guardrails, curbs, parked vehicles, road signs, road markings, roadside structures (e.g., walls, buildings, etc.), etc. The driving environment sensor 3 may also be referred to as an "ADAS sensor." ADAS stands for Advanced Driver-Assistance Systems. Specifically, the driving environment sensor 3 includes at least one of well-known object detection sensors such as a camera, a radar sensor, and a sonar.

The electronic control unit 4 is housed inside the vehicle body C1. The electronic control unit 4 is configured as an "ADAS ECU" that controls the ADAS operation of the vehicle C. ECU is an abbreviation for Electronic Control Unit or Electric Control Unit.

Specifically, the electronic control device 4 is configured as an in-vehicle computer having a processor 41 and a memory 42. The processor 41 is configured with a CPU and an MPU. The memory 42 has at least a ROM and a RAM among various non-transient physical storage media such as a ROM, a RAM, and a non-volatile rewritable memory. A non-volatile rewritable memory is a storage device such as a flash ROM that can be rewritten while the power is on but retains information in an unrewritable manner while the power is off. The electronic control device 4 is configured to control the overall operation of the in-vehicle system 1 by reading and executing a control program stored in the ROM or the non-volatile rewritable memory.

The alarm 5 is configured with a display device, a speaker, etc., for issuing various warnings for driving assistance. The vehicle control unit 6 is configured to execute longitudinal and/or lateral motion control of the host vehicle C based on the estimated path P, etc., calculated by the electronic control unit 4.

(Route Estimation Device)
The electronic control unit 4 as a course estimation device of the present invention is configured to be mounted on a host vehicle C and estimate the course of the host vehicle C. With reference to Fig. 3, the electronic control unit 4 has a vehicle speed acquisition unit 401, a measurement result acquisition unit 402, a filter 403, a characteristic setting unit 404, and an estimated course calculation unit 405 as functional configurations realized on an on-board microcomputer in relation to the calculation of an estimated course P of the host vehicle C. Hereinafter, the configuration of the electronic control unit 4 as a course estimation device of the present invention will be described in detail with reference to Figs. 1 to 3.

The vehicle speed acquisition unit 401 is configured to acquire the detection result of the vehicle speed of the host vehicle C. Specifically, the vehicle speed acquisition unit 401 is configured to acquire the vehicle speed of the host vehicle C based on a signal or information acquired from the vehicle condition sensor 2. That is, the processor 41 is configured to store the signal or information for acquiring the vehicle speed acquired from the vehicle condition sensor 2 in the RAM.

The measurement result acquisition unit 402 is adapted to acquire a measured state quantity that is a measurement result of the lateral state quantity of the host vehicle C. The "lateral state quantity" is a state quantity corresponding to the lateral movement of the host vehicle C, such as a steering angle or yaw angle. Specifically, the measurement result acquisition unit 402 is adapted to acquire periodic measurement results of the lateral state quantity of the host vehicle C based on a signal or information acquired from the vehicle state sensor 2. That is, the processor 41 is adapted to store the signal or information corresponding to the lateral state quantity of the host vehicle C acquired from the vehicle state sensor 2 in a RAM or a non-volatile rewritable memory.

The filter 403 applies low-pass filter processing to the periodic measurement results of the lateral state quantities of the vehicle C. Specifically, the filter 403 receives the measured state quantities acquired by the measurement result acquisition unit 402 from the measurement result acquisition unit 402, applies low-pass filter processing to the measured state quantities, and passes the filter output, which is the processing result, to the estimated course calculation unit 405.

The characteristic setting unit 404 sets the filter characteristic, which is the response characteristic of the filter 403, according to the measured state quantity acquired by the measurement result acquisition unit 402 or the change state of the measured state quantity. Details of the setting of the filter characteristic will be described later. The estimated path calculation unit 405 calculates the estimated path P of the host vehicle C based on the estimated state quantity, which is the filter output.

(Operation Overview)
Hereinafter, an outline of the operation of the electronic control unit 4 according to this embodiment will be described with reference to the drawings.

As described above, in the calculation of the estimated path P of the vehicle C based on the measurement results of the lateral state quantities of the vehicle C, low-pass filter processing is applied to the state quantities in order to suppress estimation errors due to fluctuations in the state quantities caused by steering wheel wobble, noise, etc. Here, for example, in situations where the driver is beginning to perform steering behavior, particularly in situations where the driver may suddenly steer (e.g., in a parking lot), there is still room for improvement in the conventional technology described in Patent Document 1 and the like.

In this regard, by estimating the driver's intention to steer from the history of measurement results of the lateral state quantities of the vehicle C and using such estimation results, it is possible to estimate a more appropriate course. Therefore, the characteristic setting unit 404 sets the filter characteristic, which is the response characteristic of the filter 403, according to the measured state quantities acquired by the measurement result acquisition unit 402 or the change state of the measured state quantities.

The filter characteristic is, for example, a filter time (i.e., a time constant). Alternatively, the filter characteristic is, for example, an estimated time Te in the following equation (1). In the following equation (1), Ym is a measured state quantity, and Ye is an estimated state quantity. The estimated state quantity Ye is the result of filtering the measured state quantity Ym, i.e., the estimated result of the lateral state quantity of the host vehicle C. Vy is the speed of change of the measured state quantity Ym, i.e., the differential value of the measured state quantity Ym. Ay is the acceleration of change of the measured state quantity Ym, i.e., the differential value of the speed of change Vy.
Ye=Ym+Te・(2・Vy+Te・Ay)/2...(1)

Figure 4 shows how the measurement results of the lateral state quantities and the estimation results due to filtering change over time. In the figure, the dashed lines show the measured state quantities, and the solid lines show the estimated state quantities.

For example, as in area A1 in FIG. 4, when the change in the same direction (e.g., right steering direction) of the measured state quantity continues for less than a predetermined time, the measured state quantity may be noise. For this reason, there is a concern that overestimation may occur if the measured state quantity is reflected in the course estimation. Therefore, when the change in the same direction in the measured state quantity continues for less than a predetermined time, the characteristic setting unit 404 sets the filter characteristic to the low response side corresponding to a large time constant. In other words, the characteristic setting unit 404 sets the filter characteristic so that the first filter characteristic, which is the filter characteristic when the change in the same direction in the measured state quantity continues for less than a predetermined time, is on the low response side compared to the second filter characteristic, which is the filter characteristic when the change continues for a predetermined time or more. Specifically, the characteristic setting unit 404 lengthens the filter time. Alternatively, the characteristic setting unit 404 shortens the estimation time Te in formula (1).

For example, as in area A2 in FIG. 4, when the measured state quantity is equal to or less than a predetermined value, the inertia of the steering wheel reduces the change at the start of steering. In this case, the characteristic setting unit 404 sets the filter characteristic to the high response side, which corresponds to a small time constant. In other words, the characteristic setting unit 404 sets the filter characteristic so that the first filter characteristic, which is the filter characteristic when the measured state quantity is less than a predetermined value, is on the high response side compared to the second filter characteristic, which is the filter characteristic when the measured state quantity is equal to or more than the predetermined value. Specifically, the characteristic setting unit 404 shortens the filter time. Alternatively, the characteristic setting unit 404 lengthens the estimated time Te in equation (1).

For example, when the change in the measured state quantity is small, as in area A3 in FIG. 4, the driver is beginning to perform steering behavior, and there is a possibility that the steering change will become large in the future. In this case, the characteristic setting unit 404 sets the filter characteristic to the high response side, which corresponds to a small time constant. Specifically, the characteristic setting unit 404 shortens the filter time. Alternatively, the characteristic setting unit 404 lengthens the estimation time Te in equation (1).

On the other hand, when the change in the measured state quantity is large, as in area A4 in FIG. 4, the driver may be in the process of changing the steering state. If the driver notices an obstacle in the direction of the change, there is a concern that overestimation may occur. Therefore, when the change in the measured state quantity is large, the characteristic setting unit 404 sets the low response side, which corresponds to a large time constant. Specifically, the characteristic setting unit 404 lengthens the filter time. Alternatively, the characteristic setting unit 404 shortens the estimation time Te in equation (1).

In this way, the characteristic setting unit 404 sets the filter characteristic to the high response side when the change in the measured state quantity is small, and sets the filter characteristic to the low response side when the change in the measured state quantity is large. In other words, the characteristic setting unit 404 sets the filter characteristic such that, in a first case and a second case in which the amount of change or the rate of change in the measured state quantity is different, the first filter characteristic, which is the filter characteristic in the first case in which the amount of change or the rate of change is smaller than in the second case, is more responsive than the second filter characteristic, which is the filter characteristic in the second case.

For example, as in area A5 in FIG. 4, when the direction of change of the measured state quantity is opposite to the polarity of the measured state quantity (i.e., steering to the right or steering to the left) (e.g., when turning the steering wheel back), there is a concern that the steering change will be large and overestimation will occur. Therefore, in this case, the characteristic setting unit 404 sets the filter characteristic to the low response side corresponding to a large time constant. In other words, the characteristic setting unit 404 sets the filter characteristic so that the first filter characteristic, which is the filter characteristic when the polarity of the measured state quantity and the direction of change of the measured state quantity are opposite, is on the low response side compared to the second filter characteristic, which is the filter characteristic when the polarity and the direction of change are the same. Specifically, the characteristic setting unit 404 lengthens the filter time. Alternatively, the characteristic setting unit 404 shortens the estimation time Te in formula (1).

Thus, according to this embodiment, in estimating the course based on the measurement results of the state quantity corresponding to the lateral movement of the vehicle C, the presence or absence of the driver's steering intention is estimated from the history of the measurement results, and the filter characteristics are set according to the estimation result. This makes it possible to improve the accuracy of the course estimation of the vehicle C more than ever before. Specifically, for example, in a scene where there is a high possibility of noise or overestimation, the filter responsiveness is reduced to calculate the estimated state quantity, making it possible to suppress the influence of noise and the occurrence of overestimation as much as possible. On the other hand, in a scene where there is a low possibility of noise or overestimation, the filter responsiveness is increased to calculate the estimated state quantity, making it possible to obtain the driver's intention in advance and perform more accurate estimation of the future. This embodiment is particularly effective in a situation where the driver has begun to perform steering behavior.

Here, when the vehicle speed is high, there are many cases where the steering change is large, and there is a concern of overestimation. For this reason, in this case, the characteristic setting unit 404 sets the filter time to the low response side, which corresponds to a large time constant. Specifically, the characteristic setting unit 404 lengthens the filter time. Alternatively, the characteristic setting unit 404 shortens the estimation time Te in equation (1). In other words, the characteristic setting unit 404 sets the filter characteristics such that the second filter characteristic, which is the filter characteristic when the vehicle speed of the host vehicle C is a second vehicle speed that is higher than the first vehicle speed, is on the low response side, compared to the first filter characteristic, which is the filter characteristic when the vehicle speed of the host vehicle C is a first vehicle speed.

To avoid overestimation, it is preferable that the estimation result be within a range that does not exceed the maximum steering angle. Therefore, in this embodiment, a guard value corresponding to the steering angle is set for the estimated state quantity. The setting of the guard value can be performed, for example, by the filter 403 or the estimated path calculation unit 405.

(Example of operation)
An example of the operation of the electronic control unit 4 according to this embodiment will be described below with reference to the flowchart shown in Fig. 5 in addition to Fig. 1 to Fig. 4. In Fig. 5, "S" is an abbreviation for "step."

The processor 41 reads out a program corresponding to the routine shown in FIG. 5 from the memory 42 and starts it repeatedly at a predetermined time interval. When the program is started, first, in step 501, the processor 41 acquires the measurement results of the lateral state quantities, i.e., the measured state quantities. Next, in step 502, the processor 41 acquires the vehicle speed of the host vehicle C.

Next, in step 503, the processor 41 sets the filter characteristics based on the measured state quantity acquired in step 501 or its change state and the vehicle speed acquired in step 502. Then, in step 504, the processor 41 executes low-pass filter processing using the filter characteristics set in step 503. Then, in step 505, the processor 41 calculates the estimated path P using the estimated state quantity, which is the filter output, and temporarily ends this routine.

In this way, the program executed by the electronic control unit 4 having the processor 41 and the memory 42 performs the following processing as the electronic control unit 4, i.e., the processor 41:
A measurement result acquisition process for acquiring a measured state quantity which is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle C;
low-pass filtering of periodic measurement results of the measured state quantity;
A characteristic setting process for setting a filter characteristic, which is a response characteristic in low-pass filter processing, according to the measured state quantity or a change state thereof;
an estimated path calculation process for calculating an estimated path P based on an estimated state quantity that is an output of the low-pass filter process;
Includes.
The electronic control unit 4 includes a processor 41 and a memory 42.
The processor 41 is
low-pass filtering of periodic measurement results of the measured state quantity;
A characteristic setting process for setting a filter characteristic, which is a response characteristic in low-pass filter processing, according to the measured state quantity or a change state thereof;
an estimated path calculation process for calculating an estimated path P based on an estimated state quantity that is an output of the low-pass filter process;
The apparatus is configured to execute the following steps:

(Modification)
The present invention is not limited to the above embodiment. Therefore, the above embodiment can be modified as appropriate. Representative modified examples will be described below. In the following description of the modified examples, differences from the above embodiment will be mainly described. In addition, the same reference numerals are used for parts that are the same or equivalent to each other in the above embodiment and the modified examples. Therefore, in the following description of the modified examples, the description of the above embodiment can be appropriately used for components having the same reference numerals as the above embodiment, unless there is a technical contradiction or special additional explanation.

The present invention is not limited to the specific device configurations shown in the above embodiments. For example, all or part of the electronic control unit 4 may be configured to include a digital circuit, such as an ASIC or FPGA, configured to enable the above-mentioned operations. ASIC stands for Application Specific Integrated Circuit. FPGA stands for Field Programmable Gate Array. In other words, in the electronic control unit 4, the on-board microcomputer portion and the digital circuit portion may coexist.

The program according to the present invention, which enables the execution of various operations, procedures, or processes described in the above embodiment, can be downloaded or upgraded via V2X communication. V2X is an abbreviation for Vehicle to X. Alternatively, such a program can be downloaded or upgraded via a terminal device provided in a manufacturing plant, a maintenance plant, a dealer, etc. of the vehicle C. Such a program can be stored on a memory card, an optical disk, a magnetic disk, etc.

In this way, each of the above functional configurations and processes may be realized by a dedicated computer provided by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, each of the above functional configurations and processes may be realized by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, each of the above functional configurations and processes may be realized by one or more dedicated computers configured by combining a processor and memory programmed to execute one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transitive tangible storage medium as instructions executed by the computer. In other words, each of the above functional configurations and processes can be expressed as a computer program including procedures for realizing it, or as a non-transitive tangible storage medium storing the program.

Therefore, the vehicle speed acquisition unit 401 and the like shown in FIG. 3 are merely functional configuration blocks that are set for the sake of convenience in order to aid in understanding the contents of the present invention. Therefore, even if these functional configuration blocks are not actually realized within the electronic control unit 4 as subroutines or hardware, the requirements of the present invention can be satisfied as long as the functions or processes specified in the present invention are realized.

The present invention is not limited to the specific operational modes shown in the above embodiment. That is, for example, depending on the result of the path estimation, there may be cases of overestimation. For this reason, for example, a path estimation based on a measured state quantity and a path estimation based on an estimated state quantity may be performed, and a collision determination based on the path estimation result based on the measured state quantity may be used to notify the driver and brake the vehicle, and a collision determination based on the path estimation result based on the estimated state quantity may be used only to notify the driver by the alarm 5.

One of the term including the velocity of change Vy and the term including the acceleration of change Ay in the above formula (1) may be omitted. Alternatively, only one of the two estimated times Te in the above formula (1) may be adjusted according to the measured state quantity or its change state. Alternatively, as an example, a filter process may be applied only to a part of the range of the lateral state quantity.

Needless to say, the elements constituting the above embodiments are not necessarily essential, except when expressly stated as essential or when it is considered to be clearly essential in principle. Furthermore, when numerical values such as the number, amount, range, etc. of components are mentioned, the present invention is not limited to those specific numerical values, except when expressly stated as essential or when it is clearly limited to a specific numerical value in principle. Similarly, when the shape, direction, positional relationship, etc. of components are mentioned, the present invention is not limited to those shapes, directions, positional relationships, etc., except when expressly stated as essential or when it is clearly limited to a specific shape, direction, positional relationship, etc.

The modified examples are not limited to the above examples. In addition, multiple modified examples may be combined with each other. Furthermore, all or part of the above embodiment and all or part of the modified examples may be combined with each other.

1 In-vehicle system 2 Vehicle state sensor 3 Driving environment sensor 4 Electronic control device (Route estimation device)
401 Vehicle speed acquisition unit 402 Measurement result acquisition unit 403 Filter 404 Characteristics setting unit 405 Estimated course calculation unit C Vehicle

Claims (18)

A path estimation device (4) configured to be mounted on a vehicle (C) and to estimate a path of the vehicle,
A measurement result acquisition unit (402) that acquires a measured state quantity that is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
A filter (403) that performs low-pass filtering on the periodic measurement results of the state quantity;
a characteristic setting unit (404) for setting a filter characteristic, which is a response characteristic of the filter, in response to the measured state quantity or a change in the measured state quantity;
an estimated path calculation unit (405) that calculates an estimated path of the host vehicle based on an estimated state quantity that is an output of the filter;
Equipped with
The characteristic setting unit sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when a duration of a change in the same direction in the measured state quantity is less than a predetermined time, is on the low response side corresponding to a larger time constant than a second filter characteristic, which is the filter characteristic when the duration is equal to or longer than the predetermined time.
Path estimation device. the characteristic setting unit sets the filter characteristics such that, in a first case and a second case in which the change amount or the change rate of the measured state quantity is different, a first filter characteristic which is the filter characteristic in the first case in which the change amount or the change rate is smaller than that in the second case is on the high response side corresponding to a smaller time constant than a second filter characteristic which is the filter characteristic in the second case.
The course estimation device according to claim 1 . A path estimation device (4) configured to be mounted on a vehicle (C) and to estimate a path of the vehicle,
A measurement result acquisition unit (402) that acquires a measured state quantity that is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
A filter (403) that performs low-pass filtering on the periodic measurement results of the state quantity;
a characteristic setting unit (404) that sets a filter characteristic, which is a response characteristic of the filter, in response to the measured state quantity or a change in the measured state quantity;
an estimated path calculation unit (405) that calculates an estimated path of the host vehicle based on an estimated state quantity that is an output of the filter;
Equipped with
the characteristic setting unit sets the filter characteristics such that, in a first case and a second case in which the change amount or the change rate of the measured state quantity is different, a first filter characteristic which is the filter characteristic in the first case in which the change amount or the change rate is smaller than that in the second case is on the high response side corresponding to a smaller time constant than a second filter characteristic which is the filter characteristic in the second case.
Path estimation device. the characteristic setting unit sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the measured state quantity is less than a predetermined value, is on the high response side corresponding to a smaller time constant than a second filter characteristic, which is the filter characteristic when the measured state quantity is equal to or greater than the predetermined value.
The course estimation device according to any one of claims 1 to 3. A path estimation device (4) configured to be mounted on a vehicle (C) and to estimate a path of the vehicle,
A measurement result acquisition unit (402) that acquires a measured state quantity that is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
A filter (403) that performs low-pass filtering on the periodic measurement results of the state quantity;
a characteristic setting unit (404) that sets a filter characteristic, which is a response characteristic of the filter, in response to the measured state quantity or a change in the measured state quantity;
an estimated path calculation unit (405) that calculates an estimated path of the host vehicle based on an estimated state quantity that is an output of the filter;
Equipped with
the characteristic setting unit sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the measured state quantity is less than a predetermined value, is on the high response side corresponding to a smaller time constant than a second filter characteristic, which is the filter characteristic when the measured state quantity is equal to or greater than the predetermined value.
Path estimation device. the characteristic setting unit sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the polarity of the measured state quantity and the change direction of the measured state quantity are opposite to each other, is on the low response side corresponding to a larger time constant than a second filter characteristic, which is the filter characteristic when the polarity and the change direction of the measured state quantity are the same.
The course estimation device according to any one of claims 1 to 5 . A path estimation device (4) configured to be mounted on a vehicle (C) and to estimate a path of the vehicle,
A measurement result acquisition unit (402) that acquires a measured state quantity that is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
A filter (403) that performs low-pass filtering on the periodic measurement results of the state quantity;
a characteristic setting unit (404) that sets a filter characteristic, which is a response characteristic of the filter, in response to the measured state quantity or a change in the measured state quantity;
an estimated path calculation unit (405) that calculates an estimated path of the host vehicle based on an estimated state quantity that is an output of the filter;
Equipped with
the characteristic setting unit sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the polarity of the measured state quantity and the change direction of the measured state quantity are opposite to each other, is on the low response side corresponding to a larger time constant than a second filter characteristic, which is the filter characteristic when the polarity and the change direction of the measured state quantity are the same.
Path estimation device. The characteristic setting unit sets the filter characteristic such that a second filter characteristic, which is the filter characteristic when the vehicle speed of the host vehicle is a second vehicle speed higher than the first vehicle speed, is on the low response side corresponding to a large time constant, compared to a first filter characteristic, which is the filter characteristic when the vehicle speed of the host vehicle is a first vehicle speed.
The course estimation device according to any one of claims 1 to 7 . A guard value is set for the estimated state quantity according to a steering angle.
The course estimation device according to any one of claims 1 to 8 . A course estimation program executed by a course estimation device (4) configured to be mounted on a vehicle (C) and to estimate a course of the vehicle, comprising:
The process executed by the course estimation device is
A measurement result acquisition process for acquiring a measured state quantity which is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
a low-pass filter process for the periodic measurement results of the state quantity;
A characteristic setting process for setting a filter characteristic, which is a response characteristic in the low-pass filter process, in response to the measured state quantity or a change state of the measured state quantity;
an estimated path calculation process for calculating an estimated path of the host vehicle based on an estimated state quantity that is an output of the low-pass filter process;
Including,
The characteristic setting process sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when a duration of the change in the same direction in the measured state quantity is less than a predetermined time, is on the low response side corresponding to a larger time constant than a second filter characteristic, which is the filter characteristic when the duration is equal to or longer than the predetermined time.
Course estimation program. The characteristic setting process sets the filter characteristics such that a first filter characteristic, which is the filter characteristic in the first case in which the change amount or the change rate of the measured state quantity is smaller than that in the second case, is on the high response side corresponding to a smaller time constant than a second filter characteristic, which is the filter characteristic in the second case, in a first case and a second case in which the change amount or the change rate of the measured state quantity is different.
The course estimation program according to claim 10. A course estimation program executed by a course estimation device (4) configured to be mounted on a vehicle (C) and to estimate a course of the vehicle, comprising:
The process executed by the course estimation device is
A measurement result acquisition process for acquiring a measured state quantity which is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
a low-pass filter process for the periodic measurement results of the state quantity;
A characteristic setting process for setting a filter characteristic, which is a response characteristic in the low-pass filter process, in response to the measured state quantity or a change in the measured state quantity;
an estimated path calculation process for calculating an estimated path of the host vehicle based on an estimated state quantity that is an output of the low-pass filter process;
Including,
The characteristic setting process sets the filter characteristics such that a first filter characteristic, which is the filter characteristic in the first case in which the change amount or the change rate of the measured state quantity is smaller than that in the second case, is on the high response side corresponding to a smaller time constant than a second filter characteristic, which is the filter characteristic in the second case, in a first case and a second case in which the change amount or the change rate of the measured state quantity is different.
Course estimation program. The characteristic setting process sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the measured state quantity is less than a predetermined value, is on the high response side corresponding to a smaller time constant than a second filter characteristic, which is the filter characteristic when the measured state quantity is equal to or greater than the predetermined value.
The course estimation program according to any one of claims 10 to 12. A course estimation program executed by a course estimation device (4) configured to be mounted on a vehicle (C) and to estimate a course of the vehicle, comprising:
The process executed by the course estimation device is
A measurement result acquisition process for acquiring a measured state quantity which is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
a low-pass filter process for the periodic measurement results of the state quantity;
A characteristic setting process for setting a filter characteristic, which is a response characteristic in the low-pass filter process, in response to the measured state quantity or a change in the measured state quantity;
an estimated path calculation process for calculating an estimated path of the host vehicle based on an estimated state quantity that is an output of the low-pass filter process;
Including,
The characteristic setting process sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the measured state quantity is less than a predetermined value, is on the high response side corresponding to a smaller time constant than a second filter characteristic, which is the filter characteristic when the measured state quantity is equal to or greater than the predetermined value.
Course estimation program. The characteristic setting process sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the polarity of the measured state quantity and the change direction of the measured state quantity are opposite to each other, is on the low response side corresponding to a larger time constant than a second filter characteristic, which is the filter characteristic when the polarity and the change direction of the measured state quantity are the same.
The course estimation program according to any one of claims 10 to 14. A course estimation program executed by a course estimation device (4) configured to be mounted on a vehicle (C) and to estimate a course of the vehicle, comprising:
The process executed by the course estimation device is
A measurement result acquisition process for acquiring a measured state quantity which is a measurement result of a state quantity corresponding to a lateral motion of the host vehicle;
a low-pass filter process for the periodic measurement results of the state quantity;
A characteristic setting process for setting a filter characteristic, which is a response characteristic in the low-pass filter process, in response to the measured state quantity or a change in the measured state quantity;
an estimated path calculation process for calculating an estimated path of the host vehicle based on an estimated state quantity that is an output of the low-pass filter process;
Including,
The characteristic setting process sets the filter characteristics such that a first filter characteristic, which is the filter characteristic when the polarity of the measured state quantity and the change direction of the measured state quantity are opposite to each other, is on the low response side corresponding to a larger time constant than a second filter characteristic, which is the filter characteristic when the polarity and the change direction of the measured state quantity are the same.
Course estimation program. The characteristic setting process sets the filter characteristics such that a second filter characteristic, which is the filter characteristic when the vehicle speed of the host vehicle is a second vehicle speed higher than the first vehicle speed, is on the low response side corresponding to a large time constant, compared to a first filter characteristic, which is the filter characteristic when the vehicle speed of the host vehicle is a first vehicle speed.
The course estimation program according to any one of claims 10 to 16. A guard value is set for the estimated state quantity according to a steering angle.
The course estimation program according to any one of claims 10 to 17.

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