Vehicle control system

Abstract

To provide a vehicle control device that stops the vehicle at the intended stopping point on an uphill slope without requiring frequent operation of the accelerator pedal. [Solution] A vehicle control device that controls the drive system of a vehicle based on the amount of operation of an operating member, comprising: an operation amount acquisition unit that acquires the amount of operation; a gradient acquisition unit that acquires the gradient of the road surface while the vehicle is traveling; and a control unit that controls the drive system so that the vehicle stops at a reference stopping distance when the gradient is uphill and the amount of operation becomes zero while the vehicle is traveling with the drive system.

Description

Technical Field

[0001] The present disclosure relates to a vehicle control device.

Background Art

[0002] When the driver removes their foot from the accelerator pedal while the vehicle is in motion, if the drive device is an engine, the fuel supply stops; if the drive device is a motor, the power supply stops, etc., and the vehicle coasts and gradually decelerates until it stops. When the driver needs to stop before that point due to reasons such as a stopped vehicle ahead or a red signal ahead, they remove their foot from the accelerator pedal and coast to a stop a predetermined distance before the stop target position.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When stopping at the stop target position by coasting while traveling uphill, if the driver removes their foot from the accelerator pedal the same distance before the stop target position as when traveling on a flat road, the deceleration (negative acceleration) is greater on the uphill than on the flat road, so the vehicle will stop before the stop target position. Therefore, on an uphill, the driver needs to frequently operate the accelerator pedal, such as putting the foot that was removed from the accelerator pedal back on the accelerator pedal and stepping on it to accelerate with the drive device, in order to stop at the stop target position.

[0005] An object of the present disclosure is to provide a vehicle control device that can stop at the position where it should stop without frequently operating the accelerator pedal on an uphill.

Means for Solving the Problems

[0006] The vehicle control device of the present disclosure is a vehicle control device that controls a vehicle drive system based on the amount of operation of an operating member, and comprises: an operation amount acquisition unit that acquires the amount of operation; a gradient acquisition unit that acquires the gradient of the road surface while the vehicle is traveling; and a control unit that controls the drive system so that the vehicle stops at a reference stopping distance when the gradient is uphill and the amount of operation becomes zero while the vehicle is traveling with the drive system.

[0007] Furthermore, the vehicle control device of the present disclosure is a vehicle control device that controls the drive unit of a vehicle based on the amount of operation of an operating member, and comprises: an operation amount acquisition unit that acquires the amount of operation; a gradient acquisition unit that acquires the gradient of the road surface while the vehicle is traveling; a surrounding conditions acquisition unit that acquires the surrounding conditions of the vehicle; a required stopping distance calculation unit that calculates the required stopping distance based on the surrounding conditions; and a control unit that controls the drive unit so that the vehicle stops at the required stopping distance when the gradient is uphill and the operation amount becomes zero while the vehicle is traveling with the drive unit. [Effects of the Invention]

[0008] According to the vehicle control device of this disclosure, the vehicle will reliably stop at the designated stopping point even when driving uphill, so the driver does not need to frequently operate the accelerator pedal. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram showing the configuration of the vehicle. [Figure 2] This is a functional configuration diagram of a vehicle control system. [Figure 3] This is a flowchart illustrating the operation of the vehicle control system. [Figure 4] This graph shows an example of how the output of the drive unit and the vehicle speed change over time. [Modes for carrying out the invention]

[0010] The embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below are all specific examples of this disclosure. Therefore, the components, their arrangement positions, and connection configurations shown in the following embodiments are examples and are not intended to limit this disclosure. Furthermore, components in the following embodiments that are not described in an independent claim will be described as optional components.

[0011] Furthermore, each figure is a schematic diagram and not necessarily a strictly accurate representation. Note that in each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified.

[0012] Figure 1 is a diagram showing the configuration of a vehicle having the vehicle control device of the present disclosure. The vehicle 100 includes a drive unit 2 for driving the vehicle 100, an accelerator pedal 3 for the driver to operate the drive unit 2, a brake 4, a detection device 5 including various sensors, a storage device 6, and a vehicle control device 1 that controls the drive unit 2 and the brake 4.

[0013] The vehicle control device 1 is a computer with a general configuration, including a processor, memory, communication device, user interface, etc.

[0014] The drive unit 2 is, for example, a hybrid drive unit having an engine 21 and a motor 22, but it may also consist of only the engine 21 or only the motor 22.

[0015] The accelerator pedal 3 is a typical accelerator pedal operated by the driver's foot and corresponds to the operating member of this disclosure. Depending on the amount the accelerator pedal 3 is pressed, fuel is supplied to the engine 21 or electricity is supplied to the motor 22, and the driving force of the drive unit 2 is transmitted to the wheels (not shown). When the foot is released from the accelerator pedal 3, the supply of fuel or electricity is stopped, and the driving force of the drive unit 2 becomes zero.

[0016] Brake 4 is a general braking device that decelerates the vehicle 100, and is a disc brake or regenerative brake, etc. Brake 4 exerts braking force according to the amount of pressure applied to the brake pedal (not shown). Brake 4 is also activated and exerts braking force under the control of the vehicle control device 1.

[0017] The detection device 5 includes an accelerator pedal operation amount detection sensor 51 for detecting the amount of operation of the accelerator pedal 3, a vehicle weight sensor 52 for detecting the weight of the vehicle 100, a speed sensor 53 for detecting the speed of the vehicle 100, a gradient sensor 54 for detecting the gradient of the road surface while the vehicle 100 is traveling, a surrounding conditions detection sensor 55 for detecting the surrounding conditions of the vehicle 100, and a position sensor 56 such as a GPS for detecting the position of the vehicle 100. The surrounding conditions detection sensor 55 is, for example, an obstacle sensor such as an ultrasonic sensor or radar for detecting obstacles ahead, or an imaging device for detecting traffic lights or signs ahead.

[0018] The storage device 6 is a general memory device, and stores information such as a gradient map 61, such as a road map containing elevation information, and a standard stopping distance table 62, which is a list of distances for different vehicle weights and speeds until the vehicle comes to a stop while coasting on a flat road. The gradient map 61 can obtain the gradient of the road surface while driving if the current position and direction of travel of the vehicle 100 are known. The standard stopping distance table 62 is created, for example, by measuring standard stopping distances for different vehicle weights and speeds in advance through experiments. Here, coasting means the state in which the vehicle is driven by inertia by the driver taking their foot off the accelerator pedal while the vehicle is in motion, and in the case of an engine-driven vehicle, this includes the state in which the vehicle is driven with the clutch engaged or disengaged, and in the case of an electric vehicle, this includes the state in which the clutch is engaged or disengaged or the state in which regenerative braking is operating or not operating.

[0019] Figure 2 is a functional configuration diagram of the vehicle control device 1. Each functional unit named "○○ unit" corresponds to a function performed by the processor of the vehicle control device 1 when it executes a control program. The operation amount acquisition unit 11 acquires the operation amount of the accelerator pedal 3 from the accelerator operation amount detection sensor 51. The operation amount is, for example, information on the rotation angle and travel distance of the accelerator pedal 3.

[0020] The gradient acquisition unit 12 acquires the gradient of the road surface on which the vehicle 100 is traveling from the gradient sensor 54 or the gradient map 61. The gradient is, for example, information on the inclination angle of the road surface.

[0021] The weight acquisition unit 13 acquires the total weight of the vehicle 100 from the vehicle weight sensor 52. The total weight may be acquired before the start of travel or during travel.

[0022] The speed acquisition unit 14 acquires the traveling speed of the vehicle 100 from the speed sensor 53. The traveling speed is measured, for example, in kilometers per hour or meters per second.

[0023] The surrounding situation acquisition unit 15 acquires the situation around the vehicle 100 from the surrounding situation detection sensor 55. The situation around the vehicle 100 refers to situations that may be related to the stop of the vehicle 100, such as the presence or absence of a stopped vehicle in front of the vehicle 100, the presence or absence of pedestrians in front of the vehicle 100, the traffic signal in front of the vehicle 100 and its color, the content of signs such as a stop sign in front of the vehicle 100, the presence or absence of a crosswalk and crossers in front of the vehicle 100, etc.

[0024] The required stop distance calculation unit 16 calculates the distance to the position where the vehicle 100 should stop based on the surrounding situation acquired by the surrounding situation acquisition unit 15. The required stop distance is, for example, the distance to a predetermined position in front of the obstacle when there is an obstacle such as a stopped vehicle or pedestrian in front, the distance to the stop line in front when there is a red traffic signal, and the distance to in front of the crosswalk when there is a crosswalk with crossers. That is, the required stop distance is the distance to the position where the vehicle must surely stop.

[0025] The predicted stop distance calculation unit 17 calculates the predicted stop distance until the vehicle 100 coasts up the slope and stops. The predicted stop distance can be calculated mechanically from the vehicle weight, speed, frictional force, and air resistance. Here, the frictional force and air resistance can be obtained in advance, for example, by experiments.

[0026] Based on the acquired information, the control unit 18 controls the drive unit 2 and the brake 4 so that the vehicle 100 moves forward by a standard stopping distance or the required stopping distance and then stops.

[0027] Next, the operation of the processor of the vehicle control device 1 of this disclosure (hereinafter sometimes simply referred to as "vehicle control device") will be explained in accordance with the flowchart in Figure 3. The vehicle control device 1 acquires the amount of operation of the accelerator pedal 3 from the accelerator operation amount detection sensor 51 (step S1). Next, the vehicle control device 1 determines whether the driver has taken their foot off the accelerator pedal 3 based on the amount of operation of the accelerator pedal 3 (step S2). Specifically, it is determined that the driver has taken their foot off the accelerator pedal 3 when the amount of operation of the accelerator pedal 3 changes from a positive value to 0. If it is not possible to determine that the driver has taken their foot off the accelerator pedal 3 (step S2 is No), the acquisition of the amount of operation of the accelerator pedal 3 is repeated.

[0028] When the driver takes their foot off the accelerator pedal 3 (step S2 is Yes), the vehicle control device 1 obtains the vehicle weight, speed, and road surface gradient from the vehicle weight sensor 52, speed sensor 53, and gradient sensor 54, respectively (step S3). In addition to obtaining the road surface gradient from the gradient sensor 54, the gradient may also be obtained from the gradient map 61.

[0029] The vehicle control device then determines whether vehicle 100 is traveling uphill based on the acquired road gradient (step S4). Specifically, it determines that vehicle 100 is traveling uphill if the road gradient is a positive value. If it is not traveling uphill (step S4 is No), the process ends.

[0030] If vehicle 100 is traveling uphill (step S4 is Yes), the stopping distance for the corresponding vehicle weight and speed is obtained from the standard stopping distance table 62 stored in the storage device 6, based on the current vehicle weight and speed, as the standard stopping distance (step S5). If there is no information on the stopping distance for the same vehicle weight and speed, the stopping distance for an approximate vehicle weight and speed may be obtained.

[0031] Next, the vehicle control device 1 acquires information about the area around the vehicle 100 from the surrounding situation detection sensor 55 (step S6). Based on the information about the area around the vehicle 100, it calculates the required stopping distance, which is the distance at which the vehicle 100 needs to stop (step S7). Next, the vehicle control device 1 calculates the expected stopping distance (step S8).

[0032] Next, the vehicle control device 1 determines whether the required stopping distance is longer than the standard stopping distance (step S9). If it is longer (step S9 is Yes), the vehicle control device 1 assists the drive unit 2 so that the vehicle 100 moves forward by the standard stopping distance and then stops (step S10). Assist control means controlling the drive unit 2 so that the vehicle does not stop before moving forward by the standard stopping distance on an uphill slope, and assists the vehicle in moving forward by the standard stopping distance and then stopping. The required amount of assist can be calculated as the output required to move forward by the difference between the standard stopping distance and the expected stopping distance and then stop. When performing assist control, the vehicle control device 1 may drive either the engine 21 or the motor 22, but it is preferable to drive the motor 22 from the viewpoint of fuel efficiency and exhaust gas reduction.

[0033] On the other hand, if the required stopping distance is less than or equal to the standard stopping distance (step S9 is No), the vehicle control device 1 determines whether the required stopping distance is shorter than the expected stopping distance (step S11). If the required stopping distance is shorter than the expected stopping distance (step S11 is Yes), the vehicle control device 1 controls the brakes 4 to stop the vehicle 100 after moving the required stopping distance (step S12). Braking control means controlling the brakes 4 so that the vehicle moves the required stopping distance on an uphill slope and then stops. The required braking amount can be calculated as the amount of braking required to stop the vehicle before the expected stopping distance, equal to the difference between the expected stopping distance and the required stopping distance.

[0034] If the required stopping distance is greater than or equal to the expected stopping distance (step S11 is No), the vehicle control device 1 assists in controlling the vehicle 100 to move forward only the required stopping distance before stopping (step S13). Assist control means controlling the drive unit 2 so that the vehicle 100 does not stop before moving forward the required stopping distance on an uphill slope, and assists in driving to move forward only the required stopping distance before stopping. The required amount of assist can be calculated as the output required to move forward beyond the expected stopping distance by the difference between the required stopping distance and the expected stopping distance.

[0035] Figure 4 is an example of a graph showing (A) the time change in the output of the drive unit 2 and (B) the time change in speed when the vehicle control device 1 of this disclosure is operating and the vehicle 100 moves uphill by coasting for a reference stopping distance and stops. In (A), up to t1, the vehicle 100 is driven by a predetermined output w0 of the drive unit 2. When the driver takes their foot off the accelerator pedal 3 at t1, the output of the drive unit 2 drops, but it is driven with an output w1 which is smaller than w0 in order to perform assist control. Then, when the vehicle 100 moves up to the reference stopping distance and stops at t2, the output of the drive unit 2 becomes 0.

[0036] On the other hand, in (B), vehicle 100 travels at a predetermined speed v0 until t1. When the driver takes their foot off the accelerator pedal 3 at t1, the speed decreases in the same way as when decelerating by coasting on a flat road (graph g0). Then, at t2, the speed of vehicle 100 becomes 0 and the vehicle stops. At this time, as shown by the dotted line g0', the vehicle may stop before t2 if the error is less than or equal to a predetermined error d. In other words, it may stop before the required stopping distance. Note that graph g1 shows the case where the vehicle decelerates by coasting and stops after traveling the expected stopping distance when the vehicle control device 1 does not perform assist control.

[0037] As described above, when the vehicle is going uphill, if the driver takes their foot off the accelerator pedal 3, the vehicle 100 will move forward by the standard stopping distance and then stop. Therefore, the driver can take their foot off the accelerator pedal 3 a predetermined distance before the target stopping position, just as they would when driving on a flat road, and there is no need to perform complex operations such as taking their foot off the accelerator pedal 3 and then pressing it again. Furthermore, if the required stopping distance is shorter than the standard stopping distance, the drive unit 2 or brake 4 is controlled to ensure that the vehicle moves forward by the required stopping distance and then stops, so the driver can stop safely simply by taking their foot off the accelerator pedal 3.

[0038] In the above embodiment, if the required stopping distance is longer than the standard stopping distance, the vehicle is stopped at the standard stopping distance. However, the vehicle may also be controlled to proceed only the required stopping distance and stop, regardless of the difference between the standard stopping distance and the required stopping distance. That is, when the driver takes their foot off the accelerator pedal 3 on an uphill slope, braking control may be performed to stop at the required stopping distance if the required stopping distance is less than the expected stopping distance, and assist control may be performed to stop at the required stopping distance if the required stopping distance is greater than or equal to the expected stopping distance. This ensures that the vehicle proceeds appropriately by the required stopping distance and stops, regardless of when the driver takes their foot off the accelerator pedal.

[0039] Furthermore, although the above embodiment was described as the vehicle stopping after traveling only the standard stopping distance or the required stopping distance, the control by the vehicle control device 1 may be stopped, for example, when the speed falls below a predetermined speed or when the driver operates the brake pedal. This allows the vehicle to stop with less discomfort for the driver.

[0040] Furthermore, in the above embodiment, the output of the drive unit 2 during assist control was kept constant at w1, but the output of the drive unit 2 during assist control does not have to be constant. That is, as long as the vehicle 100 can travel and stop within the standard stopping distance or the required stopping distance, the output does not need to be constant. For example, the output may be gradually reduced according to the remaining distance to the standard stopping distance or the required stopping distance. As a result, the output of the drive unit decreases as the speed decreases, allowing the driver to stop with less discomfort. [Industrial applicability]

[0041] This system can provide vehicles that can stop by coasting, even on uphill slopes, in a manner that closely resembles the driver's perception. [Explanation of Symbols]

[0042] 1. Vehicle control system 11 Operation amount acquisition section 12. Gradient acquisition section 13 Weight acquisition section 14 Speed ​​acquisition section 15. Surrounding Condition Acquisition Unit 16 Required stopping distance calculation section 17. Calculation unit for estimated stopping distance 18 Control Unit 2. Drive unit 21 Engine 22 motors 3. Accelerator pedal 4 Brakes 5. Detection device 51. Accelerator pedal operation amount detection sensor 52 Vehicle weight sensor 53 Speed ​​sensor 54 Gradient Sensor 55. Surroundings detection sensor 56 Position Sensor 6 Storage device 61 Gradient Map 62 Standard stopping distance table 100 vehicles

Claims

1. A vehicle control device that controls the vehicle's drive system based on the amount of operation of an operating member, A control variable acquisition unit that acquires the aforementioned control variable, A gradient acquisition unit that acquires the gradient of the road surface while the vehicle is traveling, A control unit controls the drive unit so that the vehicle stops at a standard stopping distance when the gradient is uphill and the control input becomes zero while the vehicle is traveling with the drive unit, A vehicle control device having

2. A weight acquisition unit that acquires the total weight of the vehicle, The vehicle further comprises a speed acquisition unit that acquires the speed of the vehicle, The control unit controls the drive device based on the total weight and the speed. The vehicle control device according to claim 1.

3. A surrounding conditions acquisition unit that acquires the surrounding conditions of the vehicle, The system further includes a required stopping distance calculation unit that calculates the required stopping distance based on the surrounding conditions, The control unit controls the drive unit so that the vehicle stops at the required stopping distance if the required stopping distance is shorter than the reference stopping distance. The vehicle control device according to claim 1.

4. It further includes a predicted stopping distance calculation unit that calculates the predicted stopping distance, The control unit controls the braking device instead of the drive device if the required stopping distance is shorter than the expected stopping distance. The vehicle control device according to claim 3.

5. A vehicle control device that controls the vehicle's drive system based on the amount of operation of an operating member, A control variable acquisition unit that acquires the aforementioned control variable, A gradient acquisition unit that acquires the gradient of the road surface while the vehicle is traveling, A surrounding conditions acquisition unit that acquires the surrounding conditions of the vehicle, A required stopping distance calculation unit that calculates the required stopping distance based on the surrounding conditions, A control unit controls the drive unit so that, when the gradient is uphill and the operation amount becomes zero while the vehicle is traveling with the drive unit, the vehicle stops at the required stopping distance. A vehicle control device having

6. It further includes a predicted stopping distance calculation unit that calculates the predicted stopping distance, The control unit controls the braking device instead of the drive device if the required stopping distance is shorter than the expected stopping distance. The vehicle control device according to claim 5.

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