DRIVE FORCE CONTROL DEVICE

Abstract

Drive force control device that performs a drive torque suppression control to suppress a delivered drive torque of a vehicle in response to an actuation state of an accelerator pedal, comprising: a torque control unit (11) configured to perform the drive torque suppression control when at least one accelerator pedal opening degree is greater than an accelerator pedal opening degree threshold; a direction-of-travel detection unit (12) configured to detect the direction of travel of the vehicle; and a state setting unit (13) configured to set the accelerator pedal opening degree threshold such that it is greater when the direction of travel of the vehicle detected by the direction of travel detection unit (12) is a forward direction than when the direction of travel of the vehicle is a reverse direction.

Description

[Technical field]

[0001] The present invention relates to a drive force control device. [Background of the invention]

[0002] To prevent a vehicle from starting suddenly due to driver error, a false start suppression control technique for suppressing the vehicle's drive torque is known. As such a false start suppression control technique, JP 2018-5 808 A discloses a technique for changing a threshold value of an accelerator pedal actuation speed or accelerator pedal opening degree, which represents a start suppression activation condition, in response to a relative speed or distance between the vehicle and a preceding vehicle.

[0003] DE 10 2013 106 604 A1 discloses a vehicle drive force suppression device with a central control unit comprising: an object detection unit for detecting an object located at the front or rear of the vehicle; a gear position detection unit that checks whether the transmission position is forward or reverse when the vehicle starts moving; a starting situation detection unit that detects the vehicle's situation when it starts moving; and a drive force suppression determination unit that compares the accelerator pedal depressor velocity at a given moment with a predetermined threshold to determine whether or not to suppress the drive force. The threshold pattern for the accelerator pedal depressor velocity is set such that the threshold decreases as the amount of accelerator pedal depressor increases.

[0004] US 2010 / 0023234A1 discloses a vehicle control system for the timely and correct execution of a preventative control for improper starting at a location where hazard prevention is truly necessary. An initial motion state of a vehicle is specified, in which starting or accelerating by pressing an accelerator pedal is permitted. In this initial motion state, an improper starting signal action is detected, which is indicated by the driver of the vehicle at a time prior to the point at which the vehicle actually starts moving. When the improper starting signal action is detected, an improper starting prevention output is executed.

[0005] US 2012 / 0329605 A1 discloses a shift error detection device. This device detects the actuation value of an accelerator pedal in a vehicle and a shift range selected by a shift action performed by the vehicle's driver. According to the disclosed shift error detection method, at a certain point it is determined that the accelerator pedal return operation is steeper than the operation during the normal return time because the accelerator pedal opening rate falls below a learned value, and the OFF flag for a steep accelerator pedal actuation is set to ON.

[0006] DE 11 2015 005 807 T5 discloses a vehicle control device. A sensor ECU determines whether an obstacle has been detected within a drive limit distance in the direction of travel of a vehicle. If it is determined that an obstacle has been detected, the sensor ECU performs collision avoidance control by limiting the drive force. [Summary of the invention][Problem to be solved by the invention]

[0007] Furthermore, with such a false start suppression control, there is the possibility that the false start suppression control will be activated despite an intended activation by the driver, thus worsening the driving behavior, and there is a need to suppress drive torque appropriately when activation by the driver is unintentional.

[0008] The subject matter of the present invention is therefore to provide a drive force control device that is capable of suppressing torque output due to faulty actuation and simultaneously preventing a deterioration of driving behavior. [Means of solving the problem]

[0009] To solve the problems described above, the present invention provides a drive force control device that performs a drive torque suppression control in which a delivered drive torque of a vehicle is suppressed in response to an actuation state of an accelerator pedal, comprising: a torque control unit configured to perform the drive torque suppression control when at least one degree of accelerator pedal opening is greater than an accelerator pedal opening degree threshold; a direction of travel detection unit configured to detect a direction of travel of the vehicle; and a state setting unit configured to adjust the accelerator pedal opening degree threshold such that it is greater when the direction of travel of the vehicle detected by the direction of travel detection unit is a forward direction than when the direction of travel of the vehicle is a reverse direction. [Effect of the invention]

[0010] In this way, according to the invention, a torque output due to faulty actuation can be suppressed and at the same time a deterioration of the driving behavior can be prevented. [Brief description of the characters] Fig. Figure 1 is a block diagram of a drive force control device according to an embodiment of the present invention. Fig. Figure 2 is a diagram that illustrates an example of setting a threshold value of the drive force control device according to an embodiment of the present invention. Fig. Figure 3 is a flowchart that illustrates the sequence of a state setting process of the drive force control device according to an embodiment of the present invention. Fig. Figure 4 is a flowchart illustrating the sequence of a drive torque suppression process of the drive force control device according to an embodiment of the present invention. Fig. Figure 5 is a flowchart showing the time sequence of the execution of a drive torque suppression control and the time sequence of a warning message due to a change in the accelerator pedal opening degree during the drive torque suppression process of the drive force control device according to an embodiment of the present invention. Fig. Figure 6 is a flowchart illustrating the sequence of a drive torque suppression control continuation process of the drive force control device according to an embodiment of the present invention. Fig. Figure 7 is a flowchart that depicts a time sequence of a termination of the drive torque suppression control during the drive torque suppression control continuation process of the drive force control device according to an embodiment of the present invention. [Emphasis(s) of the invention]

[0011] A drive force control device according to the embodiments of the present invention is a drive force control device that performs a drive force suppression control to suppress a delivered drive torque of a vehicle in response to an actuation state of an accelerator pedal, comprising: a torque control unit configured to perform the drive torque suppression control when at least one degree of accelerator pedal opening is greater than an accelerator pedal opening degree threshold; a direction-of-travel detection unit configured to detect a direction of travel of the vehicle; and a state-setting unit configured to set the accelerator pedal opening degree threshold such that it is greater when the direction of travel of the vehicle detected by the direction-of-travel detection unit is a forward direction than when the direction of travel of the vehicle is a reverse direction.

[0012] Accordingly, according to the invention, torque output due to faulty actuation can be suppressed and at the same time a deterioration of driving behavior can be prevented. [Versions]

[0013] In the following, a drive force control device according to embodiments of the present invention will be described in more detail with reference to the drawings.

[0014] In Fig. 1 comprises a vehicle 1 equipped with a drive force control device according to a first embodiment of the present invention, an internal combustion engine 2, a warning device 3, an electronic control unit (ECU) 4 of the engine, and a control unit 5.

[0015] The engine 2 is equipped with a plurality of cylinders. In the embodiments, the engine 2 is configured to perform a series of four strokes in each cylinder, comprising an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. In the embodiments, the vehicle 1 is propelled by the driving force of the engine 2.

[0016] The warning device 3 includes, for example, a display unit, a loudspeaker, a lamp, a counter, a buzzer and the like, and emits various types of warning signals intended for the driver (audible, visible, and the like).

[0017] The engine ECU 4 is designed as a computing unit that includes a central processing unit (CPU), a working memory (RAM), a read-only memory (ROM), a flash memory, an input port and an output port.

[0018] The ROM of the motor ECU 4 stores a program for operating the computer unit as motor ECU 4, as well as various constants and characteristic curves. This means that when the CPU executes the program stored in the ROM, the computer unit operates as motor ECU 4. Furthermore, motor ECU 4 is connected to the control unit 5, and data is transmitted and received between them.

[0019] The engine ECU 4 controls the engine 2 such that the torque output of the engine 2 assumes a torque command value set based on a torque command signal transmitted by the control unit 5. The engine ECU 4 controls the torque output of the engine 2 by controlling an injector or a throttle valve (not shown) to control a fuel injection quantity or an intake air quantity.

[0020] The control unit 5 is configured as a computing unit that includes a CPU, RAM, ROM, flash memory, input port and output port.

[0021] The ROM of control unit 5 stores a program for operating the computer unit as control unit 5, as well as various constants and characteristic curves. This means that when the CPU executes the program stored in the ROM, the computer unit operates as control unit 5. Control unit 5 is connected to the engine ECU 4, and data is transmitted and received between them.

[0022] The input port of the control unit 5 is connected to various sensors, including a front sensor 51, a rear sensor 52, an accelerator pedal opening degree sensor 53, a brake switch 54, a vehicle speed sensor 55, an engine speed sensor 56 and a shift position sensor 57.

[0023] The front sensor 51 detects a distance to an object located in front of the vehicle 1 by sending and receiving a laser beam, ultrasonic waves, millimeter waves or the like, or by imaging the front with a camera.

[0024] The rear sensor 52 detects a distance to an object located behind the vehicle 1 by sending and receiving a laser beam, ultrasonic waves, millimeter waves or the like, or by imaging the rear with a camera.

[0025] The accelerator pedal opening degree sensor 53 detects the amount of actuation of an accelerator pedal (not shown) by a driver as the accelerator pedal opening degree.

[0026] The brake switch 54 detects whether a (not shown) brake pedal is being operated by the driver.

[0027] The vehicle speed sensor 55 detects vehicle speed based on the rotational speed, e.g., of a (not shown) drive shaft. The vehicle speed sensor 55 outputs a positive vehicle speed when the vehicle 1 is moving forward and a negative vehicle speed when the vehicle 1 is moving backward.

[0028] The engine speed sensor 56 detects an engine speed, which is an engine speed of the internal combustion engine 2.

[0029] The shift position sensor 57 detects a shift position selected by the driver operating a (not shown) shift lever. A shift position could be, for example, a forward position, a reverse position, or a neutral position.

[0030] The warning device 3 is connected to the output port of the control unit 5.

[0031] In the vehicle 1 configured in this way, the control unit 5 performs a drive torque suppression control to suppress a sudden start due to incorrect operation by the driver, in which a drive torque of the motor 2 is suppressed, for example if a false start suppression condition is met, namely that a brake pedal is not actuated and an obstacle is detected within a predetermined distance in the direction of travel of the vehicle 1, and the accelerator pedal opening degree or the amount of the change in the accelerator pedal opening degree becomes greater than the threshold value.

[0032] The control unit 5 functions as a torque control unit 11, which suppresses an output of a drive torque from the motor 2 in response to a torque command signal to the motor ECU 4.

[0033] The control unit 5 determines whether the drive torque suppression control should be executed, based on an accelerator pedal opening degree threshold, which represents a threshold value of the accelerator pedal opening degree, and an accelerator pedal opening degree change amount threshold, which represents a threshold value of the change amount of the accelerator pedal opening degree.

[0034] The control unit 5 executes the drive torque suppression control when the accelerator pedal opening degree and the amount of change in accelerator pedal opening degree meet a predetermined drive torque suppression control execution condition.

[0035] For example, control unit 5 specifies as an execution condition for the drive torque suppression control that the accelerator pedal opening degree is greater than the accelerator pedal opening degree threshold.

[0036] For example, the control unit 5 can specify as an execution condition for the drive torque suppression control that the amount of change in the accelerator pedal opening degree is greater than the threshold value for the amount of change in the accelerator pedal opening degree and that the degree of opening of the accelerator pedal is greater than the threshold value for the accelerator pedal opening degree.

[0037] For example, the control unit 5 can specify as an execution condition for the drive torque suppression control that the accelerator pedal opening degree is greater than the accelerator pedal opening degree threshold or that the accelerator pedal opening degree change amount is greater than the accelerator pedal opening degree change amount threshold.

[0038] The control unit 5 functions as a direction of travel detection unit 12, which detects the direction of travel of the vehicle 1 based on the switching position detected by the switching position sensor 57.

[0039] The control unit 5 functions as a driving state determination unit 14, which determines, based on the vehicle speed detected by the vehicle speed sensor 55, whether the vehicle 1 is in a stopped state or in a driving state.

[0040] The control unit 5 functions as a state setting unit 13, which sets the accelerator pedal opening degree threshold to a higher value when the direction of travel of the vehicle 1 is a forward direction than when the direction of travel of the vehicle 1 is a reverse direction.

[0041] Since the driver tends to press the accelerator pedal harder when driving forward than when driving in reverse, it is possible to prevent the torque output caused by incorrect operation and at the same time accommodate a torque output corresponding to the driver's intention by setting a condition such that the drive torque suppression control is more difficult to execute when moving forward than when moving backward.

[0042] Since the accelerator pedal opening threshold is changed in response to forward and reverse movement, it is also possible to appropriately prevent torque output caused, for example, by incorrect actuation, even if the driver adjusts the actuation amount in response to forward and reverse movement, while maintaining a constant actuation speed in both forward and reverse movement.

[0043] The control unit 5 functions as a state setting unit 13, which sets the accelerator pedal opening degree change amount threshold to a higher value when the direction of travel of vehicle 1 is a forward direction than when the direction of travel of vehicle 1 is a reverse direction.

[0044] Since, in addition to the accelerator pedal opening degree, a further condition is specified for the amount of change in the accelerator pedal opening degree, making the drive torque suppression control more difficult to execute during forward movement than during reverse movement, it is possible to prevent torque output caused by incorrect actuation in a suitable manner during both forward and reverse movement, even in a case where the driver actsuates the accelerator pedal with an actuation characteristic in which an end actuation speed varies, but an end actuation amount remains the same.

[0045] The control unit 5 functions as a state setting unit 13, which sets the accelerator pedal opening degree threshold to a higher value when the driving state of vehicle 1 is a stopped state than when the driving state of vehicle 1 is a driving state.

[0046] Since the driver tends to press the accelerator pedal harder and faster when starting from a standstill than when driving slowly (for example, when the vehicle is parked), it is possible to prevent torque output caused by an incorrect operation and at the same time accommodate a torque output corresponding to the driver's intention by setting a condition such that the drive torque suppression control is more difficult to execute in a standstill than in a driving state.

[0047] The control unit 5 functions as a state setting unit 13, which sets the accelerator pedal opening degree change amount threshold to a higher value when the driving state of vehicle 1 is a stopped state than when the driving state of vehicle 1 is a driving state.

[0048] Since, in addition to the accelerator pedal opening degree, a further condition is set for the amount of change in the accelerator pedal opening degree, making the drive torque suppression control more difficult to execute during forward movement than during reverse movement, it is possible to prevent, for example, a torque output caused by incorrect actuation, in a suitable manner both in a starting state and in a low-speed driving state, even in a case where the driver actsuates the accelerator pedal with an actuation characteristic where the actuation speed varies but the final actuation amount remains the same, or in a case where the driver actsuates the accelerator pedal with an actuation characteristic where the actuation amount varies but the actuation speed remains the same.

[0049] The control unit 5 functions as a warning control unit 15, which issues a warning signal to the occupant of the vehicle 1 via a warning device when the accelerator pedal opening degree or accelerator pedal opening degree change amount becomes greater than a threshold value.

[0050] The control unit 5 determines whether a warning should be issued based on an accelerator pedal opening degree warning threshold, which represents a threshold value of an accelerator pedal opening degree, and an accelerator pedal opening degree change amount warning threshold, which represents a threshold value of an accelerator pedal opening degree change amount.

[0051] Control unit 5 issues a warning when the accelerator pedal opening degree and the amount of change in accelerator pedal opening degree meet a predetermined warning condition.

[0052] For example, control unit 5 specifies as a warning condition that the accelerator pedal opening degree must be greater than an accelerator pedal opening degree warning threshold.

[0053] For example, the control unit 5 can specify as a warning condition that the amount of change in the accelerator pedal opening is greater than the accelerator pedal opening warning threshold and that the accelerator pedal opening is greater than the accelerator pedal opening warning threshold.

[0054] For example, the control unit 5 can specify as a warning condition that the accelerator pedal opening degree is greater than the accelerator pedal opening degree warning threshold and / or that the accelerator pedal opening degree change amount is greater than the accelerator pedal opening degree change amount warning threshold.

[0055] Control unit 5 functions as a warning threshold setting unit 16, which sets the accelerator pedal opening degree warning threshold to a lower value than the accelerator pedal opening degree threshold. Control unit 5 functions as a warning threshold setting unit 16, which sets the accelerator pedal opening degree change amount warning threshold to a lower value than the accelerator pedal opening degree change amount threshold.

[0056] Since a warning is issued in such a configuration before the drive torque suppression control is executed, it is possible to prevent the execution of an unnecessary drive torque suppression control if the driver recognizes the incorrect operation in a timely manner.

[0057] The control unit 5 functions as a warning threshold setting unit 16, which sets the accelerator pedal opening degree warning threshold such that it is greater when the direction of travel of the vehicle 1 is a forward direction than when the direction of travel of the vehicle 1 is a reverse direction.

[0058] The control unit 5 functions as a warning threshold setting unit 16, which sets the accelerator pedal opening degree change amount warning threshold such that it is greater when the direction of travel of the vehicle 1 is a forward direction than when the direction of travel of the vehicle 1 is a reverse direction.

[0059] The control unit 5 functions as a warning threshold setting unit 16, which sets the accelerator pedal opening degree warning threshold such that it is greater when the vehicle's driving state 1 is a stopped state than when the vehicle's driving state 1 is a driving state.

[0060] The control unit 5 functions as a warning threshold setting unit 16, which sets the accelerator pedal opening degree change amount warning threshold such that it is greater when the driving state of vehicle 1 is a stopped state than when the driving state of vehicle 1 is a driving state.

[0061] The control unit 5 functions as a driving range detection unit 17, which detects a driving range based on the switching position detected by the switching position sensor 57. The driving range is selected, for example, as forward, reverse, or neutral.

[0062] The control unit 5 continues the drive torque suppression control for a predetermined period if a switching of the driving range to neutral or in an opposite direction of travel is detected during the execution of the drive torque suppression control.

[0063] Furthermore, the predetermined period described above can be a period that is preset or can be changed in response to the vehicle speed when the switching of the driving range is detected. In this case, the predetermined period described above can last until the vehicle speed reaches a predetermined value or less.

[0064] If the drive torque suppression control is stopped when the driving range is switched from a forward position to reverse or neutral position or from reverse to forward or neutral position during the execution of the drive torque suppression control, according to the driver's intention, the vehicle speed of vehicle 1 does not immediately become zero after the driving range switching, so that the vehicle continues to move in the direction of travel set before the switching and thus the vehicle approaches an obstacle while the drive torque suppression control is stopped.

[0065] If the drive torque suppression control continues when the switching of the driving range to the neutral position or the opposite direction of travel is detected during the execution of the drive torque suppression control, it is thus possible to reduce the vehicle speed by continuing the drive torque suppression control while the vehicle 1 is not traveling in the opposite direction (a distance to the obstacle is becoming shorter).

[0066] As in Fig. As shown in Figure 2, the control unit 5 stores, for example, the accelerator pedal opening degree threshold, the accelerator pedal opening degree change amount threshold, the accelerator pedal opening degree warning threshold and the accelerator pedal opening degree change amount warning threshold for each of the driving directions and driving conditions.

[0067] In Fig. 2. Each threshold is set lower in a low-speed driving condition than in a stopped condition when the direction of travel is forward; in a stopped condition when the direction of travel is reverse, it is set lower than in a low-speed driving condition when the direction of travel is forward; and in a low-speed driving condition, it is set lower than in a stopped condition when the direction of travel is reverse.

[0068] Furthermore, an accelerator pedal opening threshold θsfs in a stopped state, when the direction of travel is forward, is set to a larger value than the accelerator pedal opening threshold θsbs in a stopped state, when the direction of travel is reverse, and an accelerator pedal opening threshold θsfr in a low-speed driving state, when the direction of travel is forward, is set to a larger value than the accelerator pedal opening threshold θsbr in a low-speed driving state, when the direction of travel is reverse.

[0069] Furthermore, an accelerator pedal opening degree change amount threshold θ'sfs in a stopped state, when the direction of travel is forward, is set to a larger value than the accelerator pedal opening degree change amount threshold θ'sbs in a stopped state, when the direction of travel is reverse, and an accelerator pedal opening degree change amount threshold θ'sfr in a low-speed driving state, when the direction of travel is forward, is set to a larger value than the accelerator pedal opening degree change amount threshold θ'sbr in a low-speed driving state, when the direction of travel is reverse.

[0070] Furthermore, an accelerator pedal opening degree threshold θsfs in a stopped state, when the direction of travel is forward, is set to a larger value than an accelerator pedal opening degree threshold θsfr in a low-speed driving state, when the direction of travel is forward, and an accelerator pedal opening degree change amount threshold θ'sfs in a stopped state, when the direction of travel is forward, is set to a larger value than the accelerator pedal opening degree change amount threshold θ'sfr in a low-speed driving state, when the direction of travel is forward.

[0071] Furthermore, an accelerator pedal opening degree threshold θsbs in a stopped state, when the direction of travel is reverse, is set to a larger value than the accelerator pedal opening degree threshold θsbr in a low-speed driving state, when the direction of travel is reverse, and an accelerator pedal opening degree change amount threshold θ'sbs in a stopped state, when the direction of travel is reverse, is set to a larger value than the accelerator pedal opening degree change amount threshold θ'sbr in a low-speed driving state, when the direction of travel is reverse.

[0072] When the vehicle is traveling in reverse, it often progresses by creeping forward, and the accelerator pedal is not used heavily. This means that the accelerator pedal action is weaker when the vehicle is stationary (in a forward direction) than when traveling at low speed (in a forward direction).

[0073] For this reason, an accelerator pedal opening degree warning threshold θafr in a low-speed driving condition, when the direction of travel is forward, is set to a higher value than an accelerator pedal opening degree warning threshold θabs in a stopped condition, when the direction of travel is reverse.

[0074] Furthermore, an accelerator pedal opening degree change amount warning threshold θ'afr in a low-speed driving condition, when the direction of travel is forward, is set to a larger value than an accelerator pedal opening degree change amount warning threshold θ'abs in a stopped condition, when the direction of travel is reverse.

[0075] Furthermore, an accelerator pedal opening threshold θsfr in a low-speed driving condition, when the direction of travel is forward, is set to a larger value than an accelerator pedal opening threshold θsbs in a stopped condition, when the direction of travel is reverse.

[0076] Furthermore, an accelerator pedal opening degree change amount threshold θ'sfr in a low-speed driving condition, when the direction of travel is forward, is set to a larger value than an accelerator pedal opening degree change amount threshold θ'sbs in a stopped condition, when the direction of travel is reverse.

[0077] Subsequently, a state setting process is carried out by the drive force control device according to the embodiments with the configuration described above, with reference to the Fig. 3 described. In addition, the state setting process described below begins when the operation of the control unit 5 is started and is executed at predetermined time intervals.

[0078] In step S1, the control unit 5 detects the direction of travel of the vehicle 1 based on the switching position detected by the switching position sensor 57.

[0079] In step S2, the control unit 5 detects the driving state of the vehicle 1 based on the vehicle speed detected by the vehicle speed sensor 55.

[0080] In step S3, the control unit 5 sets the accelerator pedal opening degree threshold value based on the direction of travel of vehicle 1 and the driving condition of vehicle 1.

[0081] In step S4, the control unit 5 sets the accelerator pedal opening degree change amount threshold value based on the direction of travel of vehicle 1 and the driving condition of vehicle 1.

[0082] In step S5, the control unit 5 sets the accelerator pedal opening degree warning threshold and the accelerator pedal opening degree change amount warning threshold based on the direction of travel of vehicle 1 and the driving condition of vehicle 1 and ends the process.

[0083] As a result, a drive torque suppression process is carried out by the drive force control device according to the embodiments with reference to the Fig. 4 described. Furthermore, the drive torque suppression process described below is started when the false start suppression condition described above is met, is executed at predetermined time intervals, and is stopped when the false start suppression condition described above is not met.

[0084] In step S11, the control unit 5 detects the accelerator pedal opening degree based on the accelerator pedal opening degree sensor 53.

[0085] In step S12, the control unit calculates the amount of change in the accelerator pedal opening degree from the previous accelerator pedal opening degree and the current accelerator pedal opening degree.

[0086] In step S13, control unit 5 determines whether the accelerator pedal opening degree and the amount of change in accelerator pedal opening degree meet the warning condition described above. If it is determined that the warning condition is not met, control unit 5 terminates the process.

[0087] If in step S13 it is determined that the warning condition is met, the control unit 5 issues a warning to the warning device 3 in step S14.

[0088] In step S15, control unit 5 determines whether the accelerator pedal opening degree and the accelerator pedal opening degree change rate satisfy the drive torque suppression control execution condition described above. If it is determined that the drive torque suppression control execution condition is not satisfied, control unit 5 terminates the process.

[0089] If in step S15 it is determined that the drive torque suppression control execution condition is met, the control unit 5 executes the drive torque suppression control in step S16 and terminates the process.

[0090] Subsequently, the drive torque suppression process is described with reference to the Fig. 5 described.

[0091] Will be, as in Fig. As shown in Figure 5, an obstacle is detected within a predetermined distance in the direction of travel of vehicle 1 and the accelerator pedal is suddenly pressed, the amount of change in the accelerator pedal opening degree increases and exceeds the accelerator pedal opening degree change warning threshold at time t1 and the accelerator pedal opening degree change threshold at time t2.

[0092] If the accelerator pedal is subsequently depressed further, the accelerator pedal opening degree change at time t3 exceeds the accelerator pedal opening degree warning threshold, so that a warning is issued by warning device 3. If the accelerator pedal opening degree change at time t4 exceeds the accelerator pedal opening degree threshold, the drive torque suppression control is executed.

[0093] Subsequently, a continuation process of the drive torque suppression control by the drive force control device according to the embodiments with reference to the Fig. 6 described. Furthermore, the continuation process of the drive torque suppression control described below begins when the operation of the control unit 5 is started and is executed at predetermined time intervals.

[0094] In step S21, control unit 5 determines whether the travel range is switched to the neutral position or to the opposite direction of travel. If it is determined that the travel range is not switched to the neutral position or the opposite direction of travel, control unit 5 terminates the process.

[0095] If, in step S21, it is determined that the driving range is to be switched to the neutral position or the opposite direction of travel, the control unit 5 determines in step S22 whether the drive torque suppression control is executed. If it is determined that the drive torque suppression control is not executed, the control unit 5 terminates the process.

[0096] If in step S22 it is determined that the drive torque suppression control is executed, the control unit 5 continues the drive torque suppression control for a predetermined period in step S23.

[0097] Subsequently, the operation of the continuation process of the drive torque suppression control is described with reference to the Fig. 7 described.

[0098] As in Fig. As shown in Figure 7, if a rear obstacle is detected during a low-speed reverse drive and the driving range is switched from a reverse drive to a forward drive at time t5 during the execution of the drive torque suppression control, the drive torque suppression control is executed continuously because the drive torque suppression control is being executed.

[0099] If it is determined that vehicle 1 has stopped after the vehicle speed at time t6 has reached a predetermined value or less, the drive torque suppression control is terminated by determining that a predetermined period has ended.

[0100] Furthermore, if the engine speed decreases to a predetermined value or less during the execution of the drive torque suppression control, the driver can be notified of the reduction in engine speed via a message display or a beeping sound.

[0101] In a vehicle with a manual transmission, the engine torque suppression control system reduces engine torque to a low level. However, if no action is taken, engine failure will occur. Therefore, it is possible to prompt the driver to perform a preventative action by informing them that the engine speed will be reduced when it drops to a predetermined value or below.

[0102] Furthermore, a vehicle with a rear door, such as a truck, is equipped with a sensor to detect the open state of the rear door. In this case, the drive torque suppression control can be activated if an obstacle is detected away from the door and the sensor detects that the door is open.

[0103] With such a configuration, it is possible to avoid executing the drive torque suppression control when the door is detected as an obstacle, thus suppressing the execution of an unnecessary drive torque suppression control.

[0104] If it is possible to distinguish the door from the other obstacles using the rear sensor 52, an open state of the door can be detected based on the detection result of the rear sensor 52.

[0105] Furthermore, the present embodiments describe a case in which the drive torque of the vehicle 1 is supplied by the internal combustion engine 2. However, the same configuration can also be used in a case in which the drive torque of the vehicle 1 is supplied by a motor or the like.

[0106] The embodiments described above exemplify how the control unit 5 can perform various types of determinations or calculations based on different types of sensor information. However, the invention is not limited to this. A configuration can also be used in which the vehicle 1 includes a communication unit capable of communicating with an external device, such as an external server, performing various types of determinations or calculations using the external device based on detection information from various sensors transmitted by the communication unit, receiving the determination or calculation result via the communication unit, and executing various types of controls by using the received determination or calculation results.

[0107] Although embodiments of the present invention have been described herein, it is understood that a person skilled in the art could make modifications without departing from the scope of the present invention. All possible modifications or equivalents are to be considered as covered by the following claims. DESCRIPTION OF REFERENCE MARKS

[0108] 1 ... Vehicle, 2 ... Internal combustion engine, 3 ... Warning device, 4 ... Engine ECU, 5 ... Control unit, 11 ... Torque control unit, 12 ... Driving direction detection unit, 13 ... State setting unit, 14 ... Driving state determination unit, 15 ... Warning control unit, 16 ... Warning threshold setting unit, 17 ... Driving range detection unit, 53 ... Accelerator pedal opening degree sensor, 55 ... Vehicle speed sensor, 57 ... Gear shift position sensor

Claims

[1] Drive force control device performing drive torque suppression control to suppress a delivered drive torque of a vehicle in response to an actuation state of an accelerator pedal, comprising: a torque control unit (11) configured to perform the drive torque suppression control when at least one accelerator pedal opening degree is greater than an accelerator pedal opening degree threshold; a direction-of-travel detection unit (12) configured to detect the direction of travel of the vehicle; and a state setting unit (13) configured to set the accelerator pedal opening degree threshold such that it is greater when the direction of travel of the vehicle detected by the direction of travel detection unit (12) is a forward direction than when the direction of travel of the vehicle is a reverse direction. [2] Drive force control device according to claim 1, wherein the torque control unit (11) performs the drive torque suppression control under the additional condition that a change in the degree of opening of the accelerator pedal is greater than an accelerator pedal degree of change threshold value, and wherein the state setting unit (13) sets the accelerator pedal opening degree change amount threshold to a larger value when the direction of travel of the vehicle detected by the direction of travel detection unit (12) is a forward direction than when the direction of travel of the vehicle is a reverse direction. [3] Drive force control device performing drive torque suppression control to suppress a delivered drive torque of a vehicle in response to an actuation state of an accelerator pedal, comprising: a torque control unit (11) configured to execute the drive torque suppression control when the condition that an accelerator pedal opening degree is greater than an accelerator pedal opening degree threshold and / or the condition that a change in the accelerator pedal opening degree is greater than an accelerator pedal opening degree change amount threshold is met; a driving state determination unit (14) configured to determine whether the vehicle is in a stopped state or a driving state; and a state setting unit (13) configured to set the accelerator pedal opening degree threshold and the accelerator pedal opening degree change amount threshold to a higher value when the driving state determination unit (14) determines that the vehicle is in a stopped state than when the driving state determination unit (14) determines that the vehicle is in a driving state. [4] Drive force control device according to claim 3, wherein the torque control unit (11) performs the drive torque suppression control when the degree of opening of the accelerator pedal is greater than the accelerator pedal degree of opening threshold and the amount of change in the degree of opening of the accelerator pedal is greater than the amount of change in the accelerator pedal, and wherein, when the driving state determination unit (14) determines that the vehicle is in a stopped state, the state setting unit (13) sets the accelerator pedal opening degree threshold and the accelerator pedal opening degree change amount threshold higher than when the vehicle is in a driving state. [5] Drive force control device according to claim 2 or 4, comprising: a warning control unit (15) configured to issue a warning to an occupant when the degree of opening of the accelerator pedal and the amount of change in the degree of opening of the accelerator pedal are greater than a warning threshold; and a warning threshold setting unit (16) configured to set the warning threshold to a smaller value than the accelerator pedal opening degree threshold and the accelerator pedal opening degree change amount threshold. [6] Drive force control device according to claim 1 or 3, comprising: a driving area detection unit (17) configured to detect a driving area of ​​the vehicle, wherein the torque control unit (11) continues the drive torque suppression control for a predetermined period if the driving range detection unit (17) detects a switching of the driving range to a neutral position or an opposite direction of travel during the execution of the drive torque suppression control.

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