Method for calculating a value indicative of dynamic turning radius of curvature

• US 5,102,202 A
• Filed: 01/14/1991
• Issued: 04/07/1992
• Est. Priority Date: 01/14/1991
• Status: Expired due to Fees

• Current Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Breen, Michael T.
• Primary Examiner(s): Oberleitner, Robert J.
• Assistant Examiner(s): Young, Lee W.
• Application Number:
  US07/640,784
• Time in Patent Office: 449 Days
• Field of Search: 303/7, 303/100, 303/110, 280/432, 188/3 R, 188/112 A
• US Class Current: 303/7
• CPC Class Codes: B60G 2600/04 Means for informing, instructing or displaying
• CPC Class Codes: B60G 2800/012 Rolling condition
• CPC Class Codes: B60G 2800/24 Steering, cornering
• CPC Class Codes: B60G 2800/70 Estimating or calculating vehicle parameters or state variables
• CPC Class Codes: B60G 2800/9124 Roll-over protection systems, e.g. for warning or control
• CPC Class Codes: B60T 2230/06 Tractor-trailer swaying
• CPC Class Codes: B60T 7/20 specially for trailers, e.g. in case of uncoupling of or overrunning by trailer inertia-actuated overrun brakes B60T13/08
• CPC Class Codes: B60T 8/1708 for lorries or tractor-trailer combinations
• CPC Class Codes: B60T 8/246 Change of direction
• CPC Class Codes: B60T 8/323 Systems specially adapted for tractor-trailer combinations

Abstract

A method for calculating a value indicative of tractor dynamic turning radius of curvature (DTRC), and of the level of confidence in the determined value, is provided. Wheel speeds from a front-steer axle (40) and a rear axle (36, 38) are sensed to determine the value indicative of DTRC and the speed variance between the wheels on each side of the vehicle (VAR-L, VAR-R). The speed variance values are used to calculate a filtered value of DTRC (FDTRC) and to determine a level of confidence in the DTRC and/or FDTRC values.

Claims

1. A control method for vehicles (10) of the type comprising a pair of steerable wheels (148, 150) associated with a front-steer axle (40) and at least one rear axle (36, 38) having wheels associated therewith, wheel speed sensors (98, 100, 160, 162, 102, 104) associated with the wheels on at least two of said axles for providing input signals indicative of the rotational speed of said wheels and a control unit (70) for receiving said input signals and processing same in accordance with predetermined logic rules and issuing command output signals, said control method characterized by:

determining as a function of said wheel speeds a value (DTRC) indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature for at least one of said axles;

comparing the monitored wheel speeds on each side of the vehicle to determine a speed variance value (VAR-L, VAR-R) for each side of the vehicle;

using the speed variance values (VAR-L, VAR-R) to filter the values (DTRC) indicative of at least one of dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to calculate a filtered value (FDTRC) for said at least one of said axles; and

comparing the value indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to the filtered value for said at least one of said axles to calculate a degree of confidence (DC) for at least one of the value and the filtered value for said at least one of said axles.

2. The control method of claim 1 further comprising, only if the degree of confidence (DC) for at least one of the value indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and the filtered value for at least one axle exceeds a reference, utilizing said at least one of the value indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and the filtered value to control said vehicle.

3. A trailer brake control method for articulated vehicles (10) of the type comprising a tractor (12) and a trailer (14) connected to said tractor at an articulating connection (34/176) defining a pivot axis (176) about which the trailer is pivotable relative to the tractor, an articulation angle (AA) of said vehicle defined by the included angle defined by a longitudinally extending axis of the trailer (202) passing through said pivot axis relative to a longitudinally extending axis of the tractor (200) passing through said pivot axis, said tractor (12) including a pair of steerable wheels (148, 150) associated with a front-steer axle (40) and at least one rear-drive axle (36, 38) having wheels associated therewith, a tractor brake system, a trailer brake system, a driver operated brake effort demand device (76/78) for providing a demand input signal indicative of the magnitude of operators demand for vehicle braking, trailer brake control means (174) responsive in at least one operating mode for causing the trailer brake system to be applied with an operating force generally proportional to the magnitude of said demand input signal and in a second operating mode for causing the trailer brakes to be applied in a predetermined manner selected to increase the stability of the tractor-trailer vehicle, wheel speed sensors (98, 100, 160, 162, 102, 104) associated with the wheels of said front-steer and rear-drive axles for providing input signals indicative of the rotational speed of said wheels and a control unit (70) for receiving said input signals and processing same in accordance with predetermined logic rules and issuing command output signals, said control method characterized by:

determining (170/172) a value indicative of at least one of the articulation angle (AA) and a time derivative of the articulation angle (dAA/dt) and providing at least one articulation input signal indicative thereof;

determining as a function of said wheel speeds a value (DTRC) indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature for each of at least two of said axles;

comparing the monitored wheel speeds on each side of the vehicle to determine a speed variance value (VAR-L, VAR-R) for each side of the vehicle;

using the speed variance values (VAR-L, VAR-R) to filter the values (DTRC) indicative of at least one of dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to calculate a filtered value (FDTRC) for each of said at least two of said axles,

comparing the values indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to the filtered values for each axle to calculate a degree of confidence (DC) for at least one of said values indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and filtered value; and

only if at least the degree of confidence (DC) for the at least one of said values indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and filtered value for at least one axle exceeds a reference, allowing said control unit to issue command outputs causing said trailer brakes to be operated in said second operating mode.

4. The control method of claim 3 wherein said filtered values (FDTRC) are calculated as a function of

5. A control method for vehicles (10) of the type comprising a pair of steerable wheel (148, 150) associated with a front-steer axle (40) and at least one rear axle (36, 38) having wheels associated therewith, wheel speed sensors (98, 100, 160, 162, 102, 104) associated with the wheels on said front steer and rear axles for providing input signals and a control unit (70) for receiving said input signals and processing same in accordance with predetermined logic rules and issuing command output signals indicative of the rotational speeds of said wheels, said control method characterized by:

determining as a function of said wheel speeds a value (DTRC) indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature for at least two of said axles;

comparing the monitored wheel speeds on each side of the vehicle to determine a speed variance value (VAR-L, VAR-R) for each side of the vehicle;

using the speed variance values ((VAR-L, VAR-R) to filter the values (DTRC) indicative of at least one of dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to calculate a filtered value (FDTRC) for each of said at least two of said axles,

comparing the values indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to the filtered values for each of said at least two of said axles to calculate a degree of confidence (DC) for at least one of said values indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and filtered value for each of said at least two of said axles.

6. A trailer brake control method for articulated vehicles (10) of the type comprising a tractor (12) and a trailer (14) connected to said tractor at an articulating connection (34/176) defining a pivot axis (176) about which the trailer is pivotable relative to the tractor, said trailer having trailer brakes and a trailer brake control system associated therewith, an articulation angle (AA) of said vehicle defined by the included angle defined by a longitudinally extending axis of the trailer (202) passing through said pivot avis relative to a longitudinally extending axis of the tractor (200) passing through said pivot axis (200), said tractor (12) including a pair of steerable wheels (148, 150) associated with a front-steer axle (40) and at least one rear-drive axle (36, 38) having wheels associated therewith, a tractor brake system, a trailer brake system, a driver operated brake effort demand device (76/78) for providing a demand input signal indicative of the magnitude of operators demand for vehicle braking, trailer brake control means (174) responsive in at least one operating mode for causing the trailer brake system to be applied with an operating force generally proportional to the magnitude of said demand input signal and in a second operating mode for causing the trailer brakes to be applied in a predetermined manner selected to increase the stability of the tractor-trailer vehicle, wheel speed sensors (98, 100, 160, 102, 104) associated with the wheels in said front-steer and rear-drive axles for providing input signals indicative of the rotational speed of said wheels and a control unit (70) for receiving said input signals and processing same in accordance with predetermined logic rules and issuing command output signals, said control method characterized by:

determining as a function of said wheel speeds a value (DTRC) indicative of at lest one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature for at least two of said axles;

comparing the monitored wheel speeds on each side of the vehicle to determine a speed variance value (VAR-L, VAR-R) for each side of the vehicle;

using the speed variance values (VAR-L, VAR-R) to filter the values (DTRC) indicative of at least one of dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to calculate a filtered value (FDTRC) for each of said at least two of said axles,

comparing the values indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to the filtered values for each axle to calculate a degree of confidence (DC) for at least one of said values indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and filtered value; and

only if at least the degree of confidence (DC) for the at least one of said values indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and filtered value for at least one axle exceeds a reference, allowing said control unit to issue command outputs causing said trailer brakes to be operated in said second operating mode.

7. A control system for vehicles (10) of the type comprising a pair of steerable wheels (148, 150) associated with a front-steer axle (40) and at least one rear axle (36, 38) having wheels associated therewith, wheel speed sensors (98, 100, 160, 162, 102, 104) associated with the wheels on at least two of said axles for providing input signals indicative of the rotational speed of said wheels and a control unit (70) for receiving said input signals and processing same in accordance with predetermined logic rules and issuing command output signals, said control system characterized by:

means for determining as a function of said wheel speeds a value (DTRC) indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature for at lest one of said axles;

means for comparing the monitored wheel speeds on each side of the vehicle to determine a speed variance value ((VAR-L, VAR-R) for each side of the vehicle;

means for using the speed variance values (VAR-L, VAR-R) to filter the values (DTRC) indicative of at least one of dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to calculate a filtered value (FDTRC) for said at least one of said axles, and

means for comparing the value indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to the filtered value for said at least one of said axles to calculate a degree of confidence (DC) for at least one of the values indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and the filtered value for said at least one of said axles.

8. The control system of claim 7 further comprising means, effective only if the degree of confidence (DC) for at least one of the value indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and the filtered value for at least one axle exceeds a reference, for utilizing said at least one of the value indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and the filtered value to control said vehicle.

9. A trailer brake control system for articulated vehicles (10) of the type comprising a tractor (12) and a trailer (14) provided with trailer brakes and connected to said tractor at an articulating connection (34/176) defining a pivot axis (176) about which the trailer is pivotable relative to the tractor, an articulation angle (AA) of said vehicle defined by the included angle defined by a longitudinally extending axis of the trailer (202) passing through said pivot axis relative to a longitudinally extending axis of the tractor (200) passing through said pivot axis, said tractor (12) including a pair of steerable wheels (148, 150) associated with a front-steer axle (40) and at least one rear-drive axle (36, 38) having wheels associated therewith, a tractor brake system, a trailer brake system, a driver operated brake effort demand device (76/78) for providing a demand input signal indicative of the magnitude of operators demand for vehicle braking, trailer brake control means (174) responsive in at least one operating mode for causing the trailer brake system to be applied with an operating force generally proportional to the magnitude of said demand input signal and in a second operating mode for causing the trailer brakes to be applied in a predetermined manner selected to increase the stability of the tractor-trailer vehicle, wheel speed sensors (98, 100, 160, 162, 102, 104) associated with the wheels in said front-steer and rear-drive axles for providing input signals indicative of the rotational speed of said wheels and a control unit (70) for receiving said input signals and processing same in accordance with predetermined logic rules and issuing command output signals, said control system characterized by:

means for determining as a function of said wheel speeds a value (DTRC) indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature for at least two of said axles;

means for comparing the monitored wheel speeds on each side of the vehicle to determine a speed variance value (VAR-L, VAR-R) for each side of the vehicle;

means for using the speed variance values (VAR-L, VAR-R) to filter the values (DTRC) indicative of at least one of dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to calculate a filtered value (FDTRC) for each of said at least two of said axles,

means for comparing the values indicative of at least of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature to the filtered values for each axle to calculate a degree of confidence (DC) for at least one of said values indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and filtered value; and

means effective only if at least the degree of confidence (DC) for the at least one of said values indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and filtered value for at least one axle exceeds a reference, for allowing said control unit to issue command outputs causing said trailer brakes to be operated in said second operating mode.

10. A control method for vehicles (10) of the type comprising a pair of steerable wheels (148, 150) associated with a front-steer axle (40) and at least one rear axle (36, 36) having wheels associated therewith, wheel speed sensors (98, 100, 160, 162, 102, 104) associated with the wheels on at least two of said axles for providing input signals indicative of the rotational speed of said wheels and a control unit (70) for receiving said input signals and processing same in accordance with predetermined logic rules and issuing command output signals, said control method characterized by:

determining as a function of said wheel speeds a value (DTRC) indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature for at least one of said axles;

comparing the monitored wheel speeds on each side of the vehicle to determine a speed variance value (VAR-L, VAR-R) for each side of the vehicle; and

using the speed variance values (VAR-L, VAR-R) to calculate a degree of confidence (DC) for said value indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature for said at least one of said axles.

11. The control method of claim 10 further comprising, only if the degree of confidence (DC) for at least one of the value indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and the filtered value for at least one axle exceeds a reference, utilizing said at least one of the value indicative of at least one of the dynamic turning radius of curvature and a time derivative of the dynamic turning radius of curvature and the filtered value to control said vehicle.