Adaptive cruise system

• US 5,014,200 A
• Filed: 02/20/1990
• Issued: 05/07/1991
• Est. Priority Date: 02/20/1990
• Status: Expired due to Term

• Current Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Labuhn, Pamela I., Chundrlik, William J.
• Primary Examiner(s): Black, Thomas G.
• Application Number:
  US07/481,261
• Time in Patent Office: 441 Days
• Field of Search: 364/424.01, 364/426.04, 340/903, 340/904, 356/5, 180/168, 180/167, 180/170
• US Class Current: 701/96
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60K 31/047 the memory being digital
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: B60W 2530/00 Input parameters relating to vehicle conditions or values, not covered by groups B60W2510/00 or B60W2520/00
• CPC Class Codes: B60W 2540/30 Driving style
• CPC Class Codes: B60W 2554/801 Lateral distance
• CPC Class Codes: B60W 2754/30 Longitudinal distance
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: B60W 40/09 Driving style or behaviour
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 2013/9323 Alternative operation using light waves
• CPC Class Codes: G01S 2013/9324 Alternative operation using ultrasonic waves

Abstract

An adaptive cruise system for a vehicle maintains a desired selected operator-set speed in the absence of a detected preceding target vehicle and adjusts the vehicle speed when a target vehicle is detected to maintain a following distance that is set by the vehicle operator. An alert distance is computed that is a predetermined function of a distance based on driver reaction time. To provide for the driver selectable trailing distance, the driver reaction term of the alert distance is adjusted by the vehicle operator to achieve a desired distance to the target vehicle.

Claims

1. An adaptive cruise control system for controlling the distance from a source vehicle to a target vehicle, the system comprising in combination:

a speed sensor for sensing the speed V_S of the source vehicle;

means for sensing the distance D_A from the source vehicle to the target vehicle;

means adjustable by the source vehicle operator for providing a variable signal representing an operator reaction time T_r ;

means for determining an alert distance D_alert in accord with the expression

space="preserve" listing-type="equation">D.sub.alert =f(T.sub.r V.sub.S),

where f(T_r V_S) is a predetermined function including the term T_r V_S ;

means for determining a desired trailing distance D_D from the source vehicle to the target vehicle in accord with the expression

space="preserve" listing-type="equation">D.sub.D =D.sub.alert +X

where X is a constant distance;

means for determining a source vehicle command speed V_C to establish the desired trailing distance D_D ; and

means for controlling the speed of the source vehicle to the source vehicle command speed V_C, whereby the speed of the source vehicle is controlled to maintain the distance to the target vehicle at the desired trailing distance D_D that varies in accord with the adjustment of the driver reaction time by the source vehicle operator.

2. The system of claim 1 further including:

manually operable means for establishing an operator desired cruise speed V_D ; and

means for limiting the maximum value of the determined vehicle command speed V_C at the operator desired cruise speed.

3. An adaptive cruise control system for controlling the distance from a source vehicle to a target vehicle, the system comprising in combination:

a speed sensor for sensing the speed V_S of the source vehicle;

means for sensing the distance D_A from the source vehicle to the target vehicle;

means for sensing the relative velocity V_R between the source vehicle and the target vehicle;

means adjustable by the source vehicle operator for providing a variable signal representing an operator reaction time T_r ;

means for determining an alert distance D_alert in accord with the expression

space="preserve" listing-type="equation">D.sub.alert =(V.sub.S.sup.2 /K.sub.1)-{(V.sub.S -V.sub.R).sup.2 /K.sub.2 56 +T.sub.r V.sub.S,

where K₁ and K₂ are deceleration rate constants;

means for determining a desired trailing distance D_D from the source vehicle to the target vehicle in accord with the expression

space="preserve" listing-type="equation">D.sub.D =D.sub.alert +X

where X is a constant distance;

means for determining a source vehicle command speed V_C in accord with the expression

space="preserve" listing-type="equation">V.sub.C =K.sub.p (D.sub.D -D.sub.A)+(V.sub.S -V.sub.R)

where K_p is a gain factor; and

means for controlling the speed of the source vehicle to the source vehicle command speed V_C, whereby the speed of the source vehicle is controlled to maintain the distance to the target vehicle at the desired trailing distance D_D that varies in accord with the adjustment of the driver reaction time by the source vehicle operator.

4. An adaptive cruise control method for controlling the distance from a source vehicle to a target vehicle, the system comprising the steps of:

sensing the speed V_S of the source vehicle;

sensing the distance D_A from the source vehicle to the target vehicle;

sensing the relative velocity V_R between the source vehicle and the target vehicle;

providing an operator controlled signal representing an operator controlled reaction time T_r ;

determining an alert distance D_alert in accord with the expression

space="preserve" listing-type="equation">D.sub.alert =(V.sub.S.sup.2 /K.sub.1)-{(V.sub.S -V.sub.R).sup.2 /K.sub.2 }+T.sub.r V.sub.S,

where K₁ and K₂ are deceleration rate constants;

determining a desired trailing distance D_D from the source vehicle to the target vehicle in accord with the expression

space="preserve" listing-type="equation">D.sub.D =D.sub.alert +X

where X is a constant distance;

determining a source vehicle command speed V_C in accord with the expression

space="preserve" listing-type="equation">V.sub.C =K.sub.p (D.sub.D -D.sub.A)+(V.sub.S -V.sub.R)

where K_p is a gain factor; and

controlling the speed of the source vehicle to the source vehicle command speed V_C, whereby the speed of the source vehicle is controlled to maintain the distance to the target vehicle at the desired trailing distance D_D that varies in accord with the operator controlled reaction time.