Eaton Corporation

Michael T Breen

James Melvin Slicker

Joseph S Mazur

Jeffrey H Skorupski

Chia-Hsiang Liu

A method and system for estimating the segment length of a multi-segment vehicle such as a semi tractor trailer vehicle is disclosed. The estimate is generated when the vehicle executes a turning maneuver. The method comprises determining the turning radius of the vehicle, sensing the articulation angle between two vehicle segments, such as a tractor and a trailer, generating a length estimate, and controlling the vehicle based on the estimate. The method and system are particularly useful for vehicles with steerable trailer axles in which controlling the vehicle includes automatically steering the trailer so that the trailer wheels follow a path substantially the same as the tractor wheels thus eliminating off-tracking. Controlling the vehicle may include detecting a jackknife condition and operating the braking system.

System and method for estimating trailer length

A system and method for determining vehicle mass relative to a previous mass of the same vehicle utilizes a closed-loop control system to bring the vehicle to a controlled deceleration upon initiation of the procedure. The relative mass of the vehicle is determined by sensing the applied braking pressures at each of the vehicle axles and processing that information to generate the total braking force being applied to the wheels of the vehicle. Since a greater mass requires a greater braking force to achieve the same deceleration, the necessary braking force is indicative of the relative vehicle mass. An appropriate braking mode such as work balance, proportioning, or ABS, can then be determined based on the relative vehicle mass to better control subsequent braking maneuvers.

System and method for determining relative vehicle mass

A large articulated vehicle, such as a tractor semi-trailer truck often has a number of braking locations each having a number of brake sites. To properly balance the work performed at the various brake sites in decelerating the vehicle, it is necessary to determine the relative brake factors of each site. The brake factors characterize the braking performance for a particular delivered braking pressure. A system and method for determining the relative brake factors for such a vehicle is provided. The vehicle is decelerated at a known rate while delivered braking pressure is measured and recorded for each braking location. A system of simultaneous equations is then solved to determine the relative brake factors. Once the brake factors have been determined during a sequence of controlled braking events, subsequent braking may be modified to achieve a work-balanced braking mode.

System and method for determining relative brake factors

Optimum braking effectiveness and control of a vehicle are obtained by continually evaluating estimated values of friction coefficients as they increase with decreasing vehicle velocity during vehicle braking and by increasing brake pressure accordingly to maintain the pressure just under a value at which vehicle control is compromised. This is enhanced by determining a maximum pressure that can be applied to each brake sight while maintaining the rate of change of the articulation angle between a tractor and trailer of the vehicle equal to zero. A further enhancement is obtained by estimating critical vehicle velocity as a function of steering angle, thus enabling braking effectiveness and control to be a function of maneuvering conditions.

Method and apparatus for maximizing vehicle braking effectiveness and

A trailer stability brake control method is disclosed for an articulated vehicle 11 which involves determining values indicative of tractor turning radius of curvature (TRC), articulation angle (AA) and time derivatives thereof, a value for wheel speed variance (WSV) is determined, and then a stability indicator (SI) is determined for each of TRC and AA, and the time derivatives thereof. The later step is performed by signal processing means (63) including filter means having a cutoff frequency (.OMEGA..sub.c) with the cutoff frequency decreasing as the wheel speed variance increases, and vice versa. The trailer brake control means (125) is de-actuated whenever the stability indicator (SI) relating to the articulation angle (AA) becomes less than the wheel speed variance.

Trailer stability system and method

A friction clutch coupling an engine and a gear transmission of a vehicle is controlled by a microprocessor based circuit using logic which defines operating modes according to engine and clutch conditions. During the time of clutch closure, when the vehicle is starting from rest in a startup or launch mode, the throttle or other engine control signal is restrained from quickly responding to the accelerator pedal. This avoids engine overspeeding which results from generating high torque before sufficient clutch capacity has been achieved. The control signal is developed as a function of the pedal position under control of throttle logic which, in turn, is dependent on clutch operating modes defined by the clutch logic. The clutch operating modes are four modes for automatic clutch operation comprising touch point approach mode which prohibits a throttle signal during initial clutch movement, creep mode or startup mode after touch point occurs, and lockup mode for completing clutch closing when low clutch slip is attained. A non-automatic mode is entered before the accelerator pedal is depressed or when engine stall conditions are detected.

Clutch mode control logic

Engine control method for use with automatic clutch control

Brake wear between braking sites of a vehicle is equalized by measuring work performed at the braking sites, comparing the amount of work performed at each braking site with an average calculated for all braking sites, and increasing braking demand at any braking site performing less than the average amount of work.

Method and apparatus for equalizing vehicle brake wear

A brake control system/method for preventing or arresting and minimizing trailer brake induced trailer-swing in an articulated vehicle (10) is provided. The control system/method senses or calculates values indicative of articulation angle (AA) and/or time derivatives thereof (dAA/dt,) and indicative of vehicle dynamic turning radius of curvature (DTRC), or of steer angle (SA), and/or a time derivative thereof, and processes same to sense conditions indicative of an incipient or initial trailer brake induced trailer-swing event.

Trailer brake control

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.

Method for calculating a value indicative of dynamic turning radius of

A brake control system/method for preventing or minimizing trailer-swing (FIG. 6) in an articulated vehicle (10) is provided. The control system/method senses or calculates values indicative of articulation angle (AA) and time derivatives thereof (dAA/dt,d.sup.2 AA/dt.sup.2) and processes same to sense conditions indicative of an incipient or initial trailer brake induced trailer-swing event. An incipient or initial trailer brake induced trailer swing is sensed when the vehicle brakes are applied, the absolute value of articulation angle exceeds the absolute value of a reference value, the time derivative of articulation angle is in an opposite direction from articulation angle and/or the absolute value of one of the time derivatives of articulation angle exceeds the absolute value of a reference.

Trailer brake anti-swing system and method

A brake control system/method for preventing or arresting and minimizing trailer-swing in an articulated vehicle (10) is provided. The control system/method senses or calculates values indicative of articulation angle (AA) and time derivatives thereof (dAA/dt, d.sup.2 AA/dt.sup.2) and processes same to sense conditions indicative of an incipient or initial trailer brake induced trailer-swing event.

Trailer anti-swing system and method

A brake control system/method for preventing or arresting and minimizing trailer brake induced trailer-swing in an articulated vehicle (10) is provided. The control system/method senses or calculates values indicative of articulation angle (AA) and a second order or higher time derivative thereof (d.sup.2 AA/dt.sup.2) and processes same to sense conditions indicative of a trailer brake induced trailer-swing event.

Tractor trailer anti-trailer swing system and method

A brake control system/method for preventing or arresting and minimizing trailer-swing (FIG. 6) in an articulated vehicle (10) is provided. The control system/method senses or calculates values indicative of least one time derivative of trailer transverse movement and processes same to sense conditions indicative of an incipient or initial trailer brake induced trailer-swing event.

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Garden City, MI, United States of America

Michael T Breen