Abstract: A method for operating an electric machine of a ground vehicle includes periodically determining an aging parameter based upon a temperature of the electric machine and periodically determining a short-term aging effect based upon the periodically determined aging parameter. A long-term aging effect is determined based upon the short-term aging effect. A short-term temperature adjustment is determined based upon the short-term aging effect and a long-term temperature adjustment is determined based upon the long-term aging effect. A temperature-based derated motor torque is determined based upon the long-term temperature adjustment and the short-term temperature adjustment. Operation of the electric machine is controlled responsive to an operator command for torque based upon the temperature-based derated motor torque.

Abstract: A method for operating an electric machine of a ground vehicle includes periodically determining an aging parameter based upon a temperature of the electric machine and periodically determining a short-term aging effect based upon the periodically determined aging parameter. A long-term aging effect is determined based upon the short-term aging effect. A short-term temperature adjustment is determined based upon the short-term aging effect and a long-term temperature adjustment is determined based upon the long-term aging effect. A temperature-based derated motor torque is determined based upon the long-term temperature adjustment and the short-term temperature adjustment. Operation of the electric machine is controlled responsive to an operator command for torque based upon the temperature-based derated motor torque.

Abstract: Methods and systems are provided for assessing a vehicle transmission having a resolver. A memory is configured to store preliminary data pertaining to an error of the resolver. A processor is coupled to the memory, and is configured to determine a harmonic characteristic of the preliminary data, and to assess the vehicle transmission using the harmonic characteristic.

Abstract: A vehicle includes electrical components, current sensors which determine current flowing through the electrical components, and a control system. The control system calculates and records error index values over an interval using the currents. The control system increments a first counter with every sample in the series, increments a second counter whenever a given error index value exceeds a calibrated high threshold, and decrements the second counter whenever the given error index value is less than a calibrated low threshold. A control action, e.g., recording a PASS or FAIL value, executes when either the absolute value of the second counter or the present value of the first counter reaches a corresponding limit or threshold. A method enhances the robustness of a hybrid vehicle torque security diagnostic using the control system. The vehicle and method use a signed X of Y debouncing or error signal processing method as noted above.

Abstract: A method for monitoring operation of a vehicle including a high voltage electrical system including an electrical energy storage device electrically connected to switching circuits of an inverter device via a high voltage bus, the inverter device configured to transfer electric power to an electric machine via activation of a plurality of switch devices, includes monitoring electrical ground isolation of the high voltage electrical system during ongoing operation of the vehicle, detecting an electrical ground isolation fault in the high voltage electrical system, and detecting a location of the electrical ground isolation fault associated with at least one of the electrical energy storage device, the high voltage bus, the inverter device, and the electric machine subsequent to a vehicle key-off event.

Abstract: A method minimizes driveline disturbances in a vehicle having a motor generator unit (MGU) and a controller, which may be a motor control processor or a hybrid control processor. The method includes determining a set of motor values of the MGU, including a change in motor speed, a derivative of the change in motor speed, and a motor jerk value; calculating a corrective final torque value for the MGU as a function of the set of motor values; and commanding the corrective final torque value from the MGU during a predetermined event, e.g., engine restart. Calculations and commanding the corrective final torque value are conducted by the controller within a calibrated minimum processing loop time. A vehicle includes first and second MGUs, and a controller electrically connected to the second MGU. The controller has the algorithm for minimizing driveline disturbances as noted above.

Abstract: Methods and systems are provided for motor torque control for hybrid vehicles having a motor and a communications bus. The motor torque is controlled using a first motor torque capacity if the communications bus is healthy. The motor torque is controlled using a second motor torque capacity if the communications bus is unhealthy. The first motor torque capacity has a first absolute value. The second motor torque capacity has a second absolute value that is less than the first absolute value.

Abstract: Methods and systems for controlling motor torque in a hybrid vehicle are provided. A current sensor provides a feedback current when the sensor is operating properly. A processor controls the motor torque using the feedback current if the current sensor is operating properly. The processor controls the motor torque using a slip value for the hybrid vehicle if the current sensor is not operating properly.

Abstract: A vehicle includes electrical components, current sensors which determine current flowing through the electrical components, and a control system. The control system calculates and records error index values over an interval using the currents. The control system increments a first counter with every sample in the series, increments a second counter whenever a given error index value exceeds a calibrated high threshold, and decrements the second counter whenever the given error index value is less than a calibrated low threshold. A control action, e.g., recording a PASS or FAIL value, executes when either the absolute value of the second counter or the present value of the first counter reaches a corresponding limit or threshold. A method enhances the robustness of a hybrid vehicle torque security diagnostic using the control system. The vehicle and method use a signed X of Y debouncing or error signal processing method as noted above.

Abstract: Methods and systems are provided for assessing a vehicle transmission having a resolver. A memory is configured to store preliminary data pertaining to an error of the resolver. A processor is coupled to the memory, and is configured to determine a harmonic characteristic of the preliminary data, and to assess the vehicle transmission using the harmonic characteristic.

Abstract: Methods and systems for controlling motor torque in a hybrid vehicle are provided. A current sensor provides a feedback current when the sensor is operating properly. A processor controls the motor torque using the feedback current if the current sensor is operating properly. The processor controls the motor torque using a slip value for the hybrid vehicle if the current sensor is not operating properly.

Abstract: A hybrid electric vehicle (HEV) has an algorithm for executing a method for diagnosing a high-voltage (HV) fault condition aboard the HEV. The HEV includes a high-voltage (HV) battery, an auxiliary power module (APM), a power inverter module (PIM), and a three-phase motor/generator unit (MGU). A controller executes the method to thereby measure a DC output current from the HV battery, a DC inlet current into the APM, and a pair of AC phase currents in the MGU. The method further includes calculating a DC inlet current into the PIM using the AC phase currents, diagnosing the HV fault condition using the DC output currents and the DC inlet currents, and executing a control action in response to the diagnosed condition. The method can include shutting off the APM to determine whether the APM is the root cause of the HV fault condition.

Abstract: A method minimizes driveline disturbances in a vehicle having a motor generator unit (MGU) and a controller, which may be a motor control processor or a hybrid control processor. The method includes determining a set of motor values of the MGU, including a change in motor speed, a derivative of the change in motor speed, and a motor jerk value; calculating a corrective final torque value for the MGU as a function of the set of motor values; and commanding the corrective final torque value from the MGU during a predetermined event, e.g., engine restart. Calculations and commanding the corrective final torque value are conducted by the controller within a calibrated minimum processing loop time. A vehicle includes first and second MGUs, and a controller electrically connected to the second MGU. The controller has the algorithm for minimizing driveline disturbances as noted above.

Abstract: A method for monitoring operation of a vehicle including a high voltage electrical system including an electrical energy storage device electrically connected to switching circuits of an inverter device via a high voltage bus, the inverter device configured to transfer electric power to an electric machine via activation of a plurality of switch devices, includes monitoring electrical ground isolation of the high voltage electrical system during ongoing operation of the vehicle, detecting an electrical ground isolation fault in the high voltage electrical system, and detecting a location of the electrical ground isolation fault associated with at least one of the electrical energy storage device, the high voltage bus, the inverter device, and the electric machine subsequent to a vehicle key-off event.

Abstract: A hybrid electric vehicle (HEV) has an algorithm for executing a method for diagnosing a high-voltage (HV) fault condition aboard the HEV. The HEV includes a high-voltage (HV) battery, an auxiliary power module (APM), a power inverter module (PIM), and a three-phase motor/generator unit (MGU). A controller executes the method to thereby measure a DC output current from the HV battery, a DC inlet current into the APM, and a pair of AC phase currents in the MGU. The method further includes calculating a DC inlet current into the PIM using the AC phase currents, diagnosing the HV fault condition using the DC output currents and the DC inlet currents, and executing a control action in response to the diagnosed condition. The method can include shutting off the APM to determine whether the APM is the root cause of the HV fault condition.

Abstract: A method and an article of manufacture are provided to monitor a temperature sensing circuit and detect a fault therein. The method comprises monitoring sensor readings output from a plurality of temperature sensing circuits. An average sensor reading is determined, calculated from the sensor readings output from a subset of the temperature sensing circuits. Each of the sensor readings is compared to the average sensor reading. A fault is identified when one of the sensor readings deviates from the average sensor reading by an amount greater than a threshold, more particularly when one of the sensor readings deviates from the average sensor reading by an amount greater than the threshold at least a quantity of X times out of Y sensor readings.

Abstract: A method and an article of manufacture are provided to monitor a temperature sensing circuit and detect a fault therein. The method comprises monitoring sensor readings output from a plurality of temperature sensing circuits. An average sensor reading is determined, calculated from the sensor readings output from a subset of the temperature sensing circuits. Each of the sensor readings is compared to the average sensor reading. A fault is identified when one of the sensor readings deviates from the average sensor reading by an amount greater than a threshold, more particularly when one of the sensor readings deviates from the average sensor reading by an amount greater than the threshold at least a quantity of X times out of Y sensor readings.

Abstract: A temperature compensated magnetoresistive position sensor is disclosed. The sensor includes two magnetoresistor (MR) elements biased with magnetic flux from a permanent magnet, and connected electrically in series with a precision resistor and a voltage source. A magnetically permeable slide bar is movable to positions within a defined range adjacent to the sensor for varying the magnetic flux and changing the resistance of each MR element, while maintaining the sum of the resistances of the MR elements essentially constant. For a given slide bar position, the voltage drops appearing across the precision resistor and the MR elements are processed by a computer to determine the value for a resistance ratio, where the resistance ratio equals the resistance of one of the MR elements divided by the sum of the resistances of both MR elements at the sensor operating temperature.

Abstract: A rear wheel steering mechanism capable of independently positioning the rear wheels of a vehicle also independently corrects the toe error of each steered wheel. In the preferred embodiment, each rear wheel is steered by a separate actuator. The overall steering command for the actuators is determined at least in relation to the front steering angle, the command being constrained within predefined command limits. The actuators, on the other hand, have a control range which exceeds that of the predefined command limits. The controller which generates the steering commands is adapted to receive and store signals representing the toe error of each rear wheel from a conventional wheel alignment machine, and the controller causes the actuator to position each rear wheel as a combined function of the steering command and the respective stored toe error signals.

Abstract: A magnetic shaft angle encoder uses a gear or toothed wheel for inducing periodic electrical pulses in an inductive pickup. The teeth are evenly spaced and every tooth generates a signal as it passes the pickup. A reference tooth is slightly shorter than the others so that the period of the pulse it generates is shorter than the others and is easily detected to obtain an accurate shaft index position. Since a pulse is produced for every tooth, the pulses provide an excellent means of instantaneous speed sensing.