Wheel slip sensing and control system

Claim 2

A wheel slip detection apparatus for a vehicle having a plurality of traction motors adapted to drive separate traction wheels and having an electrical source for supplying an electrical output for operating the traction motors, the motors being electrically arranged in a plurality of parallel branches, and each branch containing a single motor or a plurality of motors in series, the apparatus including means responsive to the electrical output for providing a source signal varying as a function of source current, each branch having associated therewith means responsive to the motor current for providing a motor signal varying as a function of the motor current, the source signal having a predetermined normal relationship with each motor signal during normal wheel operation, and means associated with each branch and responsive to a function of the source signal and the respective motor signal for detecting an abnormal relationship between the source signal and the motor signal indicative of slipping of a wheel.

Claim 3

A wheel slip detection and connection apparatus for a vehicle having a plurality of series traction motors adapted to drive separate traction wheels and having an electrical source for supplying an electrical output for operating the traction motors, the motors being electrically arranged in a plurality of parallel branches, and each branch containing a single motor or a plurality of motors in series, the apparatus including means responsive to the electrical output for providing a source signal varying as a function of source current, each branch having associated therewith means responsive to the motor current therein for providing a motor signal varying as a function of the motor current, the source signal having a predetermined normal relationship with each motor signal during normal wheel operation, detector means associated with each branch and responsive to a function of the source signal and the respective motor signal for detecting an abnormal relationship between the source signal and the motor signal indicative of slipping of a wheel, and means associated with each branch and responsive to its respective detector means for altering the motor operation to correct the wheel slip when indicated by the slip signal from the detector means.

Claim 4

A wheel slip detection and connection apparatus for a vehicle having a plurality of series traction motors adapted to drive separate traction wheels and having an electrical source for supplying an electrical output for operating the traction motors, the motors being electrically arranged in a plurality of parallel branches, and each branch containing a single motor or a plurality of motors in series, the apparatus including means responsive to the electrical output for providing a source signal varying as a function of source current, each branch having associated therewith means responsive to the motor current therein for providing a motor signal varying as a function of the motor current, the source signal having a predetermined normal relationship with each motor signal during normal wheel operation, detector means associated with each branch and responsive to a function of the source signal and the respective motor signal for detecting an abnormal relationship between the source signal and the motor signal indicative of slipping of a wheel, and means associated with each branch and responsive to its respective detector means for altering the motor operation to correct the wheel slip when indicated by the slip signal from the detector means.

Claim 5

A wheel slip detection and correction apparatus for a vehicle having a plurality of series traction motors adapted to drive separate traction wheels and having an electrical source for supplying an electrical output for operating the traction motors, the motors being electrically arranged in a plurality of parallel branches, and each branch containing a single motor or a plurality of motors in series, the apparatus including means responsive to the electrical output for providing a source signal varying as a function of source current, each branch having associated therewith means responsive to the motor current therein for providing a motor signal varying as a function of the motor current, the source signal and each motor signal being scaled to be substantially equal when no wheel slipping occurs, detector means associated with each branch for comparing the respective motor signal and the source signal and for producing a wheel slip signal when the difference between the signals exceeds a determinable amount, and means associated with each branch and responsive to its respective detector means for increasing the motor field current to correct the wheel slip when indicated by the slip signal from the detector means.

Claim 6

A wheel slip detection and correction apparatus for a vehicle having a plurality of series traction motors adapted to drive separate traction wheels and having an electrical source for supplying an electrical output for operating the traction motors, the motors being electrically arranged in a plurality of parallel branches, and each branch containing a single motor or a plurality of motors in series, the apparatus including means responsive to the electrical output for providing a source signal varying as a function of source current, each branch having associated therewith means responsive to the motor current therein for providing a motor signal varying as a function of the motor current, the source signal and each motor signal being scaled to be substantially equal when no wheel slipping occurs, detector means associated with each branch for comparing the respective motor signal and the source signal and for producing a wheel slip signal when the difference between the signals exceeds a determinable amount, and means associated with each branch and responsive to its respective detector means for increasing the motor field current to correct the wheel slip when indicated by the slip signal from the detector means.

Claim 7

A wheel slip detection and correction apparatus for a vehicle having a plurality of series traction motors adapted to drive separate traction wheels and having an electrical source for supplying an electrical output for operating the traction motors, the motors being electrically arranged in a plurality of parallel branches, and each branch containing a single motor or a plurality of motors in series, the apparatus including means responsive to the electrical output for providing a source signal varying primarily in proportion to source current, each branch having associated therewith means responsive to the motor current therein for providing a motor signal varying in proportion to the motor current, the source signal being scaled to be slightly smaller than each motor signal when no wheel slipping occurs and the motor currents are substantially equal, detector means associated with each branch for comparing the respective motor signal and the source signal and for producing a wheel slip signal when the source signal exceeds the motor signal by a determinable amount indicative that the respective motor current is lower than motor current in another branch by a maximum allowable amount which indicates the respective wheel is slipping to an unacceptable degree, means for scheduling the maximum allowable difference in motor currents according to the rolling condition of the wheels including means for increasing the source signal by a value proportional to the source voltage, and means associated with each branch and responsive to its respective detector means for increasing the motor field current to correct the wheel slip when indicated by the slip signal from the detector means.

Claim 8

A wheel slip detection and correction apparatus for a vehicle having a plurality of series traction motors adapted to drive separate traction wheels and having an electrical source for supplying an electrical output for operating the traction motors, the motors being electrically arranged in a plurality of parallel branches, and each branch containing a single motor or a plurality of motors in series, the apparatus including means responsive to the electrical output for providing a source signal varying primarily in proportion to source current, each branch having associated therewith means responsive to the motor current therein for providing a motor signal varying in proportion to the motor current, the source signal being scaled to be slightly smaller than each motor signal when no wheel slipping occurs and the motor currents are substantially equal, detector means associated with each branch for comparing the respective motor signal and the source signal and for producing a wheel slip signal when the source signal exceeds the motor signal by a determinable amount indicative that the respective motor current is lower than motor current in another branch by a maximum allowable amount which indicates the respective wheel is slipping to an unacceptable degree, means for scheduling the maximum allowable difference in motor currents according to the rolling condition of the wheels including means for increasing the source signal by a value proportional to the source voltage, and means associated with each branch and responsive to its respective detector means for increasing the motor field current to correct the wheel slip when indicated by the slip signal from the detector means.

Claim 9

A wheel slip and overspeed detection and correction apparatus for a vehicle having a plurality of series traction motors adapted to drive separate traction wheels and having an electrical source for supplying an electrical output for operating the traction motors, the motors being electrically arranged in a plurality of parallel branches, and each branch containing a single motor or a plurality of motors in series, the apparatus including means responsive to the electrical output for providing a source signal varying as a function of source current and a source voltage signal varying as a function of the source voltage, each branch having associated therewith means responsive to the motor current therein for providing a motor signal varying as a function of the motor current such that the motor signal decreases with decreasing motor current when motor speed increases, the source signal having a predetermined normal relationship with each motor signal during non-slip wheel operation, means for scaling the source voltage signal to a value slightly less than the motor signal under normal motor speed conditions such that during motor overspeed conditions the decreased motor signal becomes less than the source voltage signal detector means associated with each branch and responsive to a function of the source signal and the respective motor signal for detecting an abnormal relationship between the source signal and the moTor signal indicative of slipping of a wheel and responsive to relative values of the source voltage signal and the respective motor signal for detecting a motor overspeed condition, and means associated with each branch and responsive to its respective detector means for increasing the motor field current to correct the wheel slip or overspeed when indicated by the detector means.

Claim 10

A wheel slip and overspeed detection and correction apparatus for a vehicle having a plurality of series traction motors adapted to drive separate traction wheels and having an electrical source for supplying an electrical output for operating the traction motors, the motors being electrically arranged in a plurality of parallel branches, and each branch containing a single motor or a plurality of motors in series, the apparatus including means responsive to the electrical output for providing a source signal varying as a function of source current and a source voltage signal varying as a function of the source voltage, each branch having associated therewith means responsive to the motor current therein for providing a motor signal varying as a function of the motor current such that the motor signal decreases with decreasing motor current when motor speed increases, the source signal having a predetermined normal relationship with each motor signal during non-slip wheel operation, means for scaling the source voltage signal to a value slightly less than the motor signal under normal motor speed conditions such that during motor overspeed conditions the decreased motor signal becomes less than the source voltage signal detector means associated with each branch and responsive to a function of the source signal and the respective motor signal for detecting an abnormal relationship between the source signal and the moTor signal indicative of slipping of a wheel and responsive to relative values of the source voltage signal and the respective motor signal for detecting a motor overspeed condition, and means associated with each branch and responsive to its respective detector means for increasing the motor field current to correct the wheel slip or overspeed when indicated by the detector means.

Claim 11

A wheel slip and overspeed detection and correction apparatus for a vehicle having a plurality of series traction motors adapted to drive separate traction wheel and having an electrical source for supplying an electrical output for operating the traction motors, the motors being electrically arranged in a plurality of parallel branches, and each branch containing a single motor or a plurality of motors in series, the apparatus including means responsive to the electrical output for providing a source signal varying primarily in proportion to source current and a source voltage signal varying as a function of the source voltage, each branch having associated therewith means responsive to the motor current therein for providing a motor signal varying in proportion to the motor current such that the motor signal decreases with decreasing motor current when motor speed increases, the source signal being scaled to be slightly smaller than each motor signal when no wheel slipping occurs and the motor currents are substantially equal, detector means associated with each branch for comparing the respective motor signal and the source signal and for producing a wheel slip signal when the source signal exceeds the motor signal by a determinable amount indicative that the respective motor current is lower than motor current in another branch by a maximum allowable amount and that the respective wheel is slipping to an unacceptable degree, means for scheduling the maximum allowable difference in motor currents according to the rolling condition of the wheels including means for increasing the source signal by a value proportional to the source voltage, the detector means further including means responsive to the rate of change in the difference between the motor signal and source signal for providing a wheel slip signal when wheel acceleration exceeds a predetermined value, the detector means further being responsive to relative values of the source voltage signal and the respective motor signal for detecting a motor overspeed condition and producing a slip signal when motor overspeed occurs, and means associated with each branch and responsive to its respective detector means for increasing the motor field current to correct the wheel slip when indicated by a slip signal from the detector means.

Claim 12

A wheel slip and overspeed detection and correction apparatus for a vehicle having a plurality of series traction motors adapted to drive separate traction wheel and having an electrical source for supplying an electrical output for operating the traction motors, the motors being electrically arranged in a plurality of parallel branches, and each branch containing a single motor or a plurality of motors in series, the apparatus including means responsive to the electrical output for providing a source signal varying primarily in proportion to source current and a source voltage signal varying as a function of the source voltage, each branch having associated therewith means responsive to the motor current therein for providing a motor signal varying in proportion to the motor current such that the motor signal decreases with decreasing motor current when motor speed increases, the source signal being scaled to be slightly smaller than each motor signal when no wheel slipping occurs and the motor currents are substantially equal, detector means associated with each branch for comparing the respective motor signal and the source signal and for producing a wheel slip signal when the source signal exceeds the motor signal by a determinable amount indicative that the respective motor current is lower than motor current in another branch by a maximum allowable amount and that the respective wheel is slipping to an unacceptable degree, means for scheduling the maximum allowable difference in motor currents according to the rolling condition of the wheels including means for increasing the source signal by a value proportional to the source voltage, the detector means further including means responsive to the rate of change in the difference between the motor signal and source signal for providing a wheel slip signal when wheel acceleration exceeds a predetermined value, the detector means further being responsive to relative values of the source voltage signal and the respective motor signal for detecting a motor overspeed condition and producing a slip signal when motor overspeed occurs, and means associated with each branch and responsive to its respective detector means for increasing the motor field current to correct the wheel slip when indicated by a slip signal from the detector means.