Visteon Global Technolgoies, Inc.

Ford Motor Company Limited

Ronald Paul Russ

Charles Francis Weber

Matthew Mark Mikolajczak

James Joseph Kornacki

Stephen Betts

Douglas Hughson

Jeff Turner

Systems, methods, and devices for capturing gesture-based inputs are disclosed herein. The concept employs infrared light emitting diodes (LEDs), infrared (IR) sensor, and processing of the information obtained by the interplay of the two. The processed information may be effectively translated to various gesture-based control systems, such as those employed to interact with electronic systems and displays.

Capturing gesture-based inputs

A system and method for determining a microstep rotor offset of a stepper motor is provided. The system includes a microcontroller configured to control voltage applied to a first coil and a second coil provided to operate the stepper motor; a back electro-magnetic force (BEMF) detection circuit configured to detect BEMF generated from the stepper motor. The stepper motor drives a pointer with a pointer stop, and the system is configured to: 1) home the stepper motor to the pointer stop, and 2) perform an iterative operation to determine a specific microstep associated with the microstep rotor offset.

Determining a rotor offset

A method of detecting a stall condition in a stepper motor with very little movement of an instrument pointer coupled to the stepper motor. The stepper motor rotates the instrument pointer in a first direction towards a pointer stop by a plurality of micro-steps. The stepper motor then rotates the pointer in the first direction at least one additional micro-step while monitoring a back electro-motive force (EMF) produced by the stepper motor. If the instrument pointer is abutting the pointer stop, then the stepper motor will be compressed slightly. If the back EMF is below a predetermined threshold, then the stepper motor is in a stall condition. The instrument pointer can then be micro-stepped in a second direction opposite the first direction to a micro-rotor offset value (&#x3bc;ROV) position.

Method and apparatus for stepper motor stall detection

A detector device and a method for detecting a stall condition in a stepper motor, wherein the characteristics of the back EMF are identified directly from a waveform of the back EMF, specifically a first peak of the back EMF, a valley of the back EMF, and a second peak of the rectified integral of the back EMF, to determine a condition of the stepper motor.

A detector device and a method for detecting a stall condition in a stepper motor, wherein the accumulated value of the back EMF is compared to a stall threshold when the stepper motor has exceeded a pre-determined rotational velocity threshold, the accumulated value of the back EMF representing a condition of the stepper motor, specifically a failure of the accumulated back EMF value to exceed the stall threshold indicating a stall condition of the stepper motor.

Method and apparatus for high speed stepper motor stall detection

The present invention comprises a method and apparatus for driving and homing a stepper motor. In a preferred embodiment, 24 micro step pulse width modulated (PWM) voltage signals are used to drive the coils of the stepper motor. The phases between the driving signals are 90&#xb0; out of phase. Thus, a sine/cosine methodology is used to drive the motor. Using micro-programmable pulse width modulation (PWM) levels involves the microprocessor reading stored voltage levels from a table stored in memory which corresponds to the amount of angular displacement desired by the motor. These voltage levels are then applied to the motor's coils. The microprocessor performs these operations by executing software instructions stored in memory. The software can be stored in memory located in the controller or in a separate logic block or logic chip. The magnitude of the bounce of a pointer attached to the output shaft of the motor and the magnitude of the noise generated as the pointer contacts a mechanical stop, are both directly related to the applied voltage and speed or frequency of the homing strategy. To reduce the bounce of the pointer and the generated noise to barely discernable levels, the applied voltage is reduced to between 15% and 30% of the normal driving voltage (approximately 1 volt for a 5 volt system). Additionally, the speed of homing is set to a value below the new start-stop frequency of the motor.

Re-zeroing of a stepper motor without noise or movement

A method of measuring the period of a vehicle speed signal is disclosed that includes the steps of accumulating predetermined time interval increments between first and second rising edges of the signal, calculating a remainder time interval upon detection of the second edge of the signal and adding the remainder to the accumulated increments value to obtain the period, and calculating an average period from a plurality of consecutive period measurements. If the accumulated value exceeds a predetermined maximum value before the second edge occurs, the maximum value is used in calculating the average.

Synchronous timer vehicle speed measurement

A vehicle speed measurement system (8) and method for driving a vehicle speed display responsive to a vehicle speed signal (300-334). A vehicle speed signal having a period corresponding to distance traveled by a vehicle is counted each first predetermined time period to provide a count (300-314); a preselected number of the counts are summed (316), the sum is filtered (318); the filtered sum is converted to the measurement of vehicle speed and a control signal for driving the vehicle speed display in response to the measurement is generated (320).

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Farmington Hills, MI, United States of America

Ronald Paul Russ