JP7714908B2 - Method and device for controlling acceleration/deceleration characteristics of a vehicle - Google Patents

Description

This invention relates to a vehicle acceleration/deceleration characteristic control that automatically changes the vehicle's acceleration/deceleration characteristics in response to driver input, for example, via an accelerator pedal or brake pedal.

Patent Document 1 discloses a control device for an electric vehicle that stores multiple functions in advance in a storage device that define the correspondence between accelerator pedal position and vehicle acceleration, allowing the driver to select one of them. Patent Document 1 also discloses that motor torque is corrected according to the road gradient so that the same acceleration and deceleration can be achieved on uphill and downhill roads as on flat roads.

Japanese Patent Application Publication No. 9-331604

For example, if the vehicle's acceleration/deceleration response is high in response to the driver's operation of the accelerator pedal or brake pedal, the vehicle's behavior can become difficult to handle on winding roads or mountain passes. Patent Document 1 corrects motor torque according to the road gradient, but this merely prevents the functional relationship between accelerator pedal position and vehicle acceleration from changing regardless of the road gradient (the influence of vehicle weight), and does not disclose changing the acceleration/deceleration characteristics according to road conditions.

The present invention provides a method for controlling acceleration/deceleration characteristics of a vehicle, which automatically changes the acceleration/deceleration characteristics of the vehicle in response to an operational input by a driver in accordance with at least one of information on topography, traffic environment, signals, signs, weather, and surrounding buildings, and includes the steps of:
learning the tendency of the driver's operation input in association with each piece of information, and correcting the acceleration/deceleration characteristics using the learning results;
It is determined whether the driver's corrective operation for the actual behavior of the vehicle due to the automatically changed acceleration/deceleration characteristics is small,
If there are many corrective operations, it is determined that the learning was inappropriate and re-learning is performed.

According to this invention, the tendency of the driver's operation input can be appropriately learned, and the optimal acceleration/deceleration characteristics can be set according to the conditions such as the terrain on which the vehicle is traveling, making driving the vehicle more comfortable.

FIG. 2 is a block diagram showing the configuration of a control device according to an embodiment. FIG. 2 is an explanatory diagram showing an example of the arrangement of information acquisition devices in a vehicle. FIG. 4 is an explanatory diagram of state transitions according to the first embodiment. 4 is a flowchart of control in a control operation phase in the first embodiment. FIG. 10 is an explanatory diagram of state transitions according to the second embodiment. 10 is a flowchart of control in a learning phase according to the second embodiment. 10 is a flowchart of control in a control operation phase according to the second embodiment.

One embodiment of the present invention will be described in detail below with reference to the drawings.

Figure 1 is a functional block diagram showing the configuration of a vehicle control device according to the present invention. The vehicle is, for example, an automobile powered by an internal combustion engine 1, and is generally driven by a driver. As a so-called driving assistance system, it is equipped with several functions, including the acceleration/deceleration characteristic control of the present invention.

In a preferred embodiment, the vehicle is equipped with multiple information acquisition devices 2 to acquire various information required for the driving assistance system, such as information about other vehicles and obstacles ahead of the vehicle, identification of traffic lights and signs, and conditions to the sides and rear. The information acquisition devices 2 are, for example, forward recognition cameras for recognizing conditions ahead, side recognition cameras for recognizing conditions to the sides, millimeter-wave radar or laser radar (LiDAR) for detecting objects ahead, etc., and these are generally used in appropriate combinations. Note that the vehicle may also be equipped with a single information acquisition device 2.

The vehicle is also equipped with a GPS system 3 containing highly accurate map information to obtain information about the roads on which the vehicle is traveling. In addition, as a so-called connected car, the vehicle may have a connected system that constantly exchanges various information with the outside world using information communication functions. In addition, the vehicle is also equipped with several sensors (not shown) to detect driving information about the vehicle, such as a vehicle speed sensor that detects vehicle speed, an acceleration sensor that detects vehicle acceleration (including deceleration), and a rotational speed sensor that detects the rotational speed of the internal combustion engine 1.

Information output by these information acquisition sensors 2, sensors for vehicle information (not shown), and the GPS system 3 is input to an acceleration/deceleration calculation unit 5, which includes a driving assistance controller 4. The acceleration/deceleration calculation unit 5 is composed of an engine controller 6, which controls the output or torque of the internal combustion engine 1, and a brake controller 8, which controls the vehicle's braking device 7. Information on the opening or depression amount of an accelerator pedal 9 and a brake pedal 10, which are input members operated by the driver, is input to the acceleration/deceleration calculation unit 5. The driving assistance controller 4 has multiple driving assistance functions that assist the driver in driving operations. For example, the driving assistance controller 4 realizes an auto-cruise control function that automatically controls vehicle speed without accelerator operation, a lane departure prevention function that detects lanes and warns or avoids lane departure, an automatic brake control function that avoids or mitigates the risk of a collision, and more.

The acceleration/deceleration unit 11, which realizes the acceleration and deceleration of the vehicle, is composed of the internal combustion engine 1 and brake device 7 described above. During acceleration/deceleration characteristic control, which automatically changes the acceleration/deceleration characteristics according to the situation, the acceleration/deceleration calculation unit 5 provides the acceleration/deceleration unit 11 with target acceleration (i.e., driving force) or deceleration (i.e., braking force) command values so that appropriate acceleration/deceleration characteristics are obtained in response to the driver's operation input of the accelerator pedal 9 or brake pedal 10. In other words, the internal combustion engine 1 and brake device 7 are controlled via the engine controller 6 and brake controller 8, and the target acceleration or deceleration is achieved. Note that deceleration can also be obtained by the so-called engine braking action of the internal combustion engine 1.

Figure 2 shows an example of an information acquisition device 2 mounted on a vehicle. The information acquisition device 2 includes a forward recognition camera 22 facing forward of the vehicle body 21, a wide-angle side recognition camera 23 also facing forward of the vehicle body 21 and having a wide viewing angle, a pair of side recognition cameras 24 facing the sides of the vehicle body 21, and a radar 25 facing forward of the vehicle body 21. The forward recognition camera 22 and the wide-angle side recognition camera 23 are integrated into a single module. Figure 2 also shows an example of the locations of the acceleration/deceleration calculation unit 5 and the controller of the GPS system 3.

Using the detection information from the information acquisition device 2, the GPS system 3, and information from connected systems, the acceleration/deceleration calculation unit 5 can obtain information on the terrain, traffic environment, traffic lights, signs, weather, and surrounding buildings. The acceleration/deceleration characteristics of the vehicle are modified in response to driver inputs based on this information. Topographical information includes whether the road is straight or curved, the curvature of the road, and the gradient of the road. Traffic environment information includes intersections, traffic volume, whether the road is urban or mountainous, whether it is a highway or not, whether there is congestion, whether it is a one-way street, the presence or absence of obstacles, the distance between the vehicle and other vehicles, the relative vehicle speed between the vehicle and other vehicles, the acceleration of other vehicles, the average speed of the traffic ahead of the vehicle, the vehicle congestion status, the number of lanes, etc. Note that the present invention is not necessarily limited to using all of this information.

When determining terrain information, traffic light information, road sign information, traffic environment information, and weather information within the vehicle itself, this can be determined, for example, by combining the above-mentioned cameras with image processing technology and machine learning. When using a connected system, this information can also be determined by receiving surrounding information from an external source. It is also possible to determine the surrounding terrain by combining detection information from the above-mentioned cameras, radar, or laser radar (LiDAR) with three-dimensional map information and using so-called SLAM technology.

Sign information mainly includes speed limit information and stop signs related to vehicle behavior. Weather information preferably mainly includes information on the presence or absence of snow or rain and the amount of snow or rain. Building information includes, for example, hospitals, schools, museums, fire stations, and police stations. This building information can be obtained, for example, from map information from the GPS system 3.

Figure 3 is an explanatory diagram of state transitions in the first embodiment. When the driver turns off the automatic correction function for acceleration/deceleration characteristics, the vehicle is driven in correction control inactive mode M1. In this case, the vehicle accelerates and decelerates according to the reference characteristics (reference correlation) in response to driver input using the accelerator pedal 9, etc. When the driver turns on the automatic correction function for acceleration/deceleration characteristics, the vehicle transitions to correction control active mode M2, entering control active phase M21. When the automatic correction function for acceleration/deceleration characteristics is turned off, the vehicle returns to correction control inactive mode M1. Note that an appropriate switch or the like can be provided to select between on and off as described above.

Figure 4 is a flowchart showing the processing flow during control operation phase M21 in this first embodiment. In step 1, information such as the above-mentioned terrain, traffic environment, traffic signals, signs, weather, and surrounding buildings is acquired or detected. Next, in step 2, the optimal acceleration/deceleration rate is calculated based on this acquired information. Then, in step 3, the vehicle's acceleration/deceleration characteristics in response to driver inputs such as accelerator pedal 9 are corrected taking this optimal acceleration/deceleration rate into consideration.

For example, when a vehicle enters a curved road, the driver will generally attempt to decelerate the vehicle. However, if the vehicle's actual deceleration is insufficient compared to the curvature of the curved road, the driver will need to depress the brake pedal 10 midway through the curved road. Conversely, if the vehicle's actual deceleration is excessive, the driver will need to depress the accelerator pedal 9 midway through the curved road, preventing smooth vehicle behavior. In the above embodiment, the vehicle's deceleration is corrected based on the curvature of the curved road that the driver is about to enter, enabling smooth driving.

Regarding weather information, for example, if snow is detected, the acceleration/deceleration response to driver inputs will be reduced to prevent sudden acceleration and deceleration in order to suppress slippage. The amount of snowfall may also be taken into consideration.

In a traffic environment that includes other vehicles, for example, if the relative speed with respect to the preceding vehicle is high (the vehicle's speed is high compared to the speed of the preceding vehicle), the vehicle deceleration is corrected to be greater when the accelerator pedal 9 is released or released. Conversely, if the acceleration of the preceding vehicle is high, the acceleration response to the driver's accelerator operation is corrected to be greater, thereby improving the ability to follow the preceding vehicle.

In addition, if the congestion around the vehicle is judged to be high, a high deceleration rate may be required, such as for a sudden stop, so the vehicle deceleration rate is corrected to be greater when the accelerator pedal 9 is released or released.

When detecting buildings, such as a school or hospital, the system will correct responsiveness to operational inputs to prevent sudden acceleration, as it predicts that children or hospital users will be passing through.

Next, a second embodiment will be described with reference to Figures 5 to 7. In the second embodiment, the driver's operational input tendencies are learned in association with each piece of information, and the acceleration/deceleration characteristics are corrected using the results of this learning.

Figure 5 is an explanatory diagram of state transitions in the second embodiment. When the driver turns off the automatic correction function for acceleration/deceleration characteristics, the vehicle is driven in correction control inactive mode M1. In this case, the vehicle accelerates and decelerates according to the reference characteristics (reference correlation) in response to driver input via the accelerator pedal 9, etc. When the driver turns on the automatic correction function for acceleration/deceleration characteristics, the vehicle transitions to correction control active mode M2. In the second embodiment, correction control active mode M2 includes a learning phase M22 that learns the driver's input trends, and a control active phase M21 that uses the results of this learning. When learning is completed in learning phase M22, the vehicle transitions to control active phase M21, and if relearning is required during control active phase M21, the vehicle transitions to learning phase M22.

Figure 6 is a flowchart showing the processing flow during learning phase M22 in the second embodiment. In step 11, it is determined whether the driver is operating the accelerator pedal 9, etc. If the determination is YES, the process proceeds to step 12, where records are created of the driver's operation amount of the accelerator pedal 9 or brake pedal 10, vehicle speed, acceleration, etc. At this time, each record is created in association with information such as the terrain, traffic environment, signals, signs, weather, surrounding buildings, etc., as mentioned above. In step 13, it is determined whether a sufficient number of records have been accumulated, and steps 11 and 12 are repeated until a sufficient number of records have been collected. Once a sufficient number of records have been accumulated, the process proceeds to step 14, where the driver's characteristics are determined in association with information such as terrain.

Figure 7 is a flowchart showing the processing flow during control operation phase M21 in the second embodiment. First, in step 21, it is determined whether learning has been completed, and if learning has not been completed, the system waits until learning is complete. If learning has been completed, the system proceeds to step 22, where information such as the terrain, traffic environment, traffic signals, signs, weather, and surrounding buildings is acquired or detected. Next, in step 23, the optimal acceleration/deceleration rate is calculated based on this acquired information and the learning results (driver's operating tendencies). Then, in step 24, the vehicle's acceleration/deceleration characteristics in response to driver operation inputs such as those on the accelerator pedal 9 are corrected taking this optimal acceleration/deceleration rate into consideration.

For example, if the learning results show that the driver prefers a high response to operational inputs under certain circumstances, the vehicle's acceleration and deceleration characteristics are corrected to achieve a relatively high response.

In the next step, step 25, it is determined whether the driver made few corrective actions in response to the actual vehicle behavior (acceleration/deceleration). If there were many corrective actions, the system proceeds to step 26 and performs relearning. That is, if the actual acceleration based on the acceleration/deceleration characteristics automatically corrected using information such as terrain and learning results is too small in response to the initial driver input, such as depression of the accelerator pedal 9, the driver will perform a corrective action such as further increasing the depression of the accelerator pedal 9. Conversely, if the actual acceleration is too large, the driver will perform a corrective action such as depressing the brake pedal 10. If there are many such corrective actions, it is possible that the learning was inappropriate, so relearning is performed.

The above describes in detail one embodiment of the present invention, but the present invention is not limited to the above embodiment and various modifications are possible.

For example, while the vehicle in the above embodiment uses an internal combustion engine 1 as a driving source, the acceleration/deceleration characteristic control of the present invention can also be applied to hybrid vehicles and electric vehicles. In hybrid vehicles and electric vehicles, deceleration can also be achieved by regenerative braking.

In addition, the vehicle may be configured so that acceleration and deceleration can be performed with a single pedal, rather than having separate accelerator pedal 9 and brake pedal 10.

Note that while the above-described embodiment illustrates a large number of information acquisition devices 2 and information, the present invention does not necessarily require all of these devices and information; it is sufficient to acquire at least one piece of information related to acceleration/deceleration characteristics.

REFERENCE SIGNS LIST 1 internal combustion engine 2 information acquisition device 3 GPS system 4 driving assistance controller 5 acceleration/deceleration calculation unit 6 engine controller 7 braking device 8 brake controller 9 accelerator pedal 10 brake pedal

Claims (8)

A vehicle acceleration/deceleration characteristic control method that automatically changes the acceleration/deceleration characteristics of a vehicle in response to an operation input by a driver in accordance with at least one of information on topography, traffic environment, traffic signals, signs, weather, and surrounding buildings , comprising:
learning the tendency of the driver's operation input in association with each piece of information, and correcting the acceleration/deceleration characteristics using the learning results;
It is determined whether the driver's corrective operation for the actual behavior of the vehicle due to the automatically changed acceleration/deceleration characteristics is small,
If there are many correction operations, the learning is deemed inappropriate and re-learning is performed.
A method for controlling acceleration and deceleration characteristics of a vehicle. 2. The method for controlling acceleration/deceleration characteristics of a vehicle according to claim 1 , wherein said acceleration/deceleration characteristics are changed in accordance with information about a terrain. 2. The method for controlling acceleration/deceleration characteristics of a vehicle according to claim 1 , wherein said acceleration/deceleration characteristics are changed in accordance with information on topography and traffic environment. 2. The method for controlling acceleration/deceleration characteristics of a vehicle according to claim 1 , wherein said acceleration/deceleration characteristics are changed in accordance with information on topography, traffic environment, signals and signs. 2. The method for controlling acceleration/deceleration characteristics of a vehicle according to claim 1 , wherein the acceleration/deceleration characteristics are changed in accordance with information on topography, traffic environment, signals, signs, weather, and surrounding buildings. 6. The method for controlling acceleration/deceleration characteristics of a vehicle according to claim 1 , wherein the information on the terrain includes at least one of whether the road is a straight road or a curved road, the curvature of the road, and the gradient of the road. The vehicle acceleration/deceleration characteristic control method according to any one of claims 1 and 3 to 5, wherein the information on the traffic environment includes at least one of traffic volume, whether the vehicle is in an urban area, whether the vehicle is in a mountainous area, whether the vehicle is on a highway, whether the road is one-way, whether there are obstacles, the distance between the vehicle and another vehicle, the relative vehicle speed between the vehicle and another vehicle, the acceleration of the other vehicle, the average speed of the traffic flow ahead of the vehicle, the vehicle congestion state, and the number of lanes. an input device operated by a driver to accelerate or decelerate the vehicle;
a drive unit that drives the vehicle;
an information acquisition device that acquires at least one piece of information from among topography, traffic environment, traffic signals, signs, weather, and surrounding buildings;
a controller that automatically changes the acceleration/deceleration characteristics of the vehicle in response to an operation input by the driver, in accordance with at least one of the acquired information on the topography, traffic environment, traffic signals, signs, weather, and surrounding buildings;
Equipped with
The above controller is
learning the tendency of the driver's operation input in association with each piece of information, and correcting the acceleration/deceleration characteristics using the learning results;
It is determined whether the driver's corrective operation for the actual behavior of the vehicle due to the automatically changed acceleration/deceleration characteristics is small,
If there are many correction operations, the learning is deemed inappropriate and re-learning is performed.
Vehicle acceleration/deceleration characteristic control device.