Driving assist system and method with accelerator pedal reaction force control

• US 7,162,349 B2
• Filed: 01/06/2003
• Issued: 01/09/2007
• Est. Priority Date: 01/10/2002
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Yamamura, Tomohiro, Hijikata, Shunsuke, Kitazaki, Satoshi
• Primary Examiner(s): Chin; Gary
• Application Number:
  US10/336,802
• Publication Number:
  US 20030135317A1
• Time in Patent Office: 1,464 Days
• Field of Search: 701/70, 701/96, 701/36, 701/301, 340/435, 340/436, 340/903, 180/167, 180/169, 180/170
• US Class Current: 701/70
• CPC Class Codes: B60K 26/021 with means for providing feel, e.g. by changing pedal force characteristics
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60K 31/18 including a device to audibly, visibly, or otherwise signal the existence of unusual or unintended speed to the driver of the vehicle devices primarily intended for indicating speed to other traffic B60Q1/54
• CPC Class Codes: B60W 2050/143 Alarm means
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2754/30 Longitudinal distance
• CPC Class Codes: B60W 30/09 Taking automatic action to avoid collision, e.g. braking and steering
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/931 of land vehicles

Abstract

A driving assist system for assisting manual effort by an operator to operate an accelerator pedal of a motor vehicle, the driving assist system comprises a data acquisition sub-system acquiring data including information on state of the motor vehicle and information on environment in a field around the motor vehicle. Control logic determines the degree of risk in the field around the motor vehicle in response to the acquired data. An actuator is provided, which is operable in response to a command for generating reaction force at the accelerator pedal. Control logic simply increases an increment of reaction force between a first reaction force increment and a second reaction force increment as the determined degree of risk grows from a predetermined cutoff value to a predetermined critical value to determine the command for regulating the actuator to realize the increment in reaction force. The first reaction force increment has a first magnitude in an area of a lower limit of a predetermined range, in magnitude, of increment in reaction force, which the vehicle operator can perceive through the sense of touch during depressing the accelerator pedal. The second reaction force increment has a second magnitude in an area of an upper limit of the predetermined range.

Claims

1. A driving assist system for assisting manual effort by an operator to operate an accelerator pedal of a motor vehicle, the driving assist system comprising:

a data acquisition sub-system acquiring data including information on state of the motor vehicle and information on environment in a field around the motor vehicle;

control logic for determining the degree of risk in the field around the motor vehicle in response to the acquired data;

an actuator operable in response to a command for generating reaction force at the accelerator pedal; and

control logic for simply increasing an increment of said reaction force between a first reaction force increment and a second reaction force increment as the determined degree of risk grows from a predetermined cutoff value to a predetermined critical value to determine the command for regulating the actuator to realize the increment in said reaction force, the first reaction force increment having a first magnitude in an area of a lower limit of a predetermined range, in magnitude, of increment in said reaction force, which the vehicle operator can perceive through the sense of touch during depressing the accelerator pedal, the second reaction force increment having a second magnitude in an area of an upper limit of the predetermined range.

2. The driving assist system as claimed in claim 1, wherein the control logic for simply increasing an increment in reaction force varies the increment in said reaction force as an exponential function of the determined degree of risk.

3. The driving assist system as claimed in claim 1, wherein the control logic for determining the degree of risk determines one of the degree of first risk that is expressed by an equation including, as a variable, the reciprocal of a time headway and the degree of second risk that is expressed by an equation, including as a variable, the reciprocal of a deviation of vehicle speed of the motor vehicle from a vehicle speed limit.

4. The driving assist system as claimed in claim 1, wherein the control logic for simply increasing an increment in reaction force determines a reaction force base as a function of accelerator pedal position of the accelerator pedal, determines the increment in response to the determined degree of risk, and adding the determined increment to the determined reaction force base to determine the reaction force to be realized by the actuator.

5. The driving assist system as claimed in claim 1, wherein the control logic for simply increasing an increment in said reaction force permits the increment in reaction force up to an upper limit increment when the degree of risk has grown to the critical value, the upper limit increment being greater than the second reaction force increment.

6. The driving assist system as claimed in claim 1, further comprising a longitudinal control unit that sets, as a critical accelerator pedal position, an accelerator pedal position of the accelerator pedal when vehicle speed of the motor vehicle has matched vehicle speed of the preceding vehicle, and wherein the longitudinal control unit carries out ordinary control by regulating output torque of an engine of the motor vehicle in response to the accelerator pedal position when the accelerator pedal position is less than or equal to the critical accelerator pedal position, and carries out intervehicle spacing control with a target intervehicle spacing decreasing as the accelerator pedal position increases when the accelerator pedal position has exceeded the critical accelerator pedal position.

7. The driving assist system as claimed in claim 4, wherein further comprising a longitudinal control unit that sets, as a critical accelerator pedal position, an accelerator pedal position of the accelerator pedal when vehicle speed of the motor vehicle has matched vehicle speed of the preceding vehicle, and wherein the longitudinal control unit carries out ordinary control by regulating output torque of an engine of the motor vehicle in response to the accelerator pedal position when the accelerator pedal position is less than or equal to the critical accelerator pedal position, and carries out intervehicle spacing control with a target intervehicle spacing decreasing as the accelerator pedal position increases when the accelerator pedal position has exceeded the critical accelerator pedal position.

8. The driving assist system as claimed in claim 6, wherein the longitudinal control unit has an accelerator pedal reference position that is greater than the critical accelerator pedal position, and wherein the longitudinal control unit carries out said ordinary control by regulating said output torque of the engine of the motor vehicle in response to the accelerator pedal position to override the intervehicle spacing control when the accelerator pedal position has exceeded the accelerator pedal reference position.

9. The driving assist system as claimed in claim 8, wherein the control logic for determining the degree of risk determines the degree of first risk that is expressed by an equation including, as variables, the reciprocal of a time to collision and the reciprocal of a time headway for use in increasing the increment in said reaction force during carrying out the ordinary control, and wherein the control logic for determining the degree of risk determines the degree of second risk that is expressed by an equation, including as a variable, the reciprocal of the time headway during carrying out the intervehicle spacing control.

10. The driving assist system as claimed in claim 4, wherein the control logic for simply increasing an increment in said reaction force varies the increment in reaction force as an exponential function of the determined degree of risk.

11. The driving assist system as claimed in claim 4, wherein the control logic for determining the degree of risk determines one of the degree of first risk that is expressed by an equation, including as a variable, the reciprocal of a time headway and the degree of second risk that is expressed by an equation, including as a variable, the reciprocal of a deviation of vehicle speed of the motor vehicle from a vehicle speed limit.

12. The driving assist system as claimed in claim 4, wherein the control logic for simply increasing an increment in reaction force permits the increment in said reaction force up to an upper limit increment when the degree of risk has grown to the critical value, the upper limit increment being greater than the second reaction force increment.

13. The driving assist system as claimed in claim 7, wherein the longitudinal control unit has an accelerator pedal reference position that is greater than the critical accelerator pedal position, and wherein the longitudinal control unit carries out said ordinary control by regulating said output torque of the engine of the motor vehicle in response to the accelerator pedal position to override the intervehicle spacing control when the accelerator pedal position has exceeded the accelerator pedal reference position.

14. The driving assist system as claimed in claim 13, wherein the control logic;

for determining the degree of risk determines the degree of first risk that is expressed by an equation including, as variables, the reciprocal of a time to collision and the reciprocal of a time headway for use in increasing the increment in said reaction force during carrying out the ordinary control, and wherein the control logic for determining the degree of risk determines the degree of second risk that is expressed by an equation, including as a variable, the reciprocal of the time headway during carrying out the intervehicle spacing control.

15. A driving assist method for assisting manual effort by an operator to operate an accelerator pedal of a motor vehicle, the driving assist method comprising:

acquiring data including information on state of the motor vehicle and information on environment in a field around the motor vehicle;

determining the degree of risk in the field around the motor vehicle in response to the acquired data;

generating reaction force at the accelerator pedal; and

simply increasing an increment of said reaction force between a first reaction force increment and a second reaction force increment as the determined degree of risk grows from a predetermined cutoff value to a predetermined critical value to determine the command for regulating the actuator to realize the increment in said reaction force, the first reaction force increment having a first magnitude in an area of a lower limit of a predetermined range, in magnitude, of increment in said reaction force, which the vehicle operator can perceive through the sense of touch during depressing the accelerator pedal, the second reaction force increment having a second magnitude in an area of an upper limit of the predetermined range.

16. A driving assist system for assisting manual effort by an operator to operate an accelerator pedal of a motor vehicle, the driving assist system comprising:

means for acquiring data including information on state of the motor vehicle and information on environment in a field around the motor vehicle;

means for determining the degree of risk in the field around the motor vehicle in response to the acquired data;

means for generating reaction force at the accelerator pedal; and

means for simply increasing an increment of said reaction force between a first reaction force increment and a second reaction force increment as the determined degree of risk grows from a predetermined cutoff value to a predetermined critical value to determine the command for regulating the actuator to realize the increment in said reaction force, the first reaction force increment having a first magnitude in an area of a lower limit of a predetermined range, in magnitude, of increment in said reaction force, which the vehicle operator can perceive through the sense of touch during depressing the accelerator pedal, the second reaction force increment having a second magnitude in an area of an upper limit of the predetermined range.