Abstract: Methods of calibrating strapdown heading sensors and strapdown heading sensors are provided. The methods include compensating raw sensor data generated by sensors of an uncalibrated strapdown heading sensor to compensate for errors in an instrument frame of the strapdown heading sensor. The strapdown heading sensor is put in a target apparatus and output data is compensated to compensate for errors in an apparatus frame relative to the instrument frame. The strapdown heading sensors include a housing and a compass module having a first sensor configured to detect a magnetic field of the Earth and a second sensor configured to detect a gravitational force of the Earth. The first sensor and the second sensor are each passively isolated from bending and/or flexing of the housing such that an alignment between the first sensor and the second sensor is not disturbed due to the bending and/or flexing.

Abstract: An attitude sensor system with automatic bias correction having a primary attitude sensor wherein the primary attitude sensor comprises at least one accelerometer and an auxiliary sensor system configured to automatically estimate a bias of the accelerometer of the primary attitude sensor such that the resulting error is removed from an output of the attitude sensor system.

Abstract: Methods of calibrating strapdown heading sensors and strapdown heading sensors are provided. The methods include compensating raw sensor data generated by sensors of an uncalibrated strapdown heading sensor to compensate for errors in an instrument frame of the strapdown heading sensor. The strapdown heading sensor is put in a target apparatus and output data is compensated to compensate for errors in an apparatus frame relative to the instrument frame. The strapdown heading sensors include a housing and a compass module having a first sensor configured to detect a magnetic field of the Earth and a second sensor configured to detect a gravitational force of the Earth. The first sensor and the second sensor are each passively isolated from bending and/or flexing of the housing such that an alignment between the first sensor and the second sensor is not disturbed due to the bending and/or flexing.

Abstract: Methods of calibrating strapdown heading sensors and strapdown heading sensors are provided. The methods include compensating raw sensor data generated by sensors of an uncalibrated strapdown heading sensor to compensate for errors in an instrument frame of the strapdown heading sensor. The strapdown heading sensor is put in a target apparatus and output data is compensated to compensate for errors in an apparatus frame relative to the instrument frame. The strapdown heading sensors include a housing and a compass module having a first sensor configured to detect a magnetic field of the Earth and a second sensor configured to detect a gravitational force of the Earth. The first sensor and the second sensor are each passively isolated from bending and/or flexing of the housing such that an alignment between the first sensor and the second sensor is not disturbed due to the bending and/or flexing.

Abstract: Methods of calibrating strapdown heading sensors and strapdown heading sensors are provided. The methods include compensating raw sensor data generated by sensors of an uncalibrated strapdown heading sensor to compensate for errors in an instrument frame of the strapdown heading sensor. The strapdown heading sensor is put in a target apparatus and output data is compensated to compensate for errors in an apparatus frame relative to the instrument frame. The strapdown heading sensors include a housing and a compass module having a first sensor configured to detect a magnetic field of the Earth and a second sensor configured to detect a gravitational force of the Earth. The first sensor and the second sensor are each passively isolated from bending and/or flexing of the housing such that an alignment between the first sensor and the second sensor is not disturbed due to the bending and/or flexing.

Abstract: An attitude sensor system with automatic bias correction having a primary attitude sensor wherein the primary attitude sensor comprises at least one accelerometer and an auxiliary sensor system configured to automatically estimate a bias of the accelerometer of the primary attitude sensor such that the resulting error is removed from an output of the attitude sensor system.

Abstract: A strapdown heading sensor includes an elongated housing and a compass module at least partially positioned within an inner cavity of the elongated housing. The compass module is cantilevered within the inner cavity of the elongated housing.

Abstract: An attitude sensor system with automatic bias correction having a primary attitude sensor wherein the primary attitude sensor comprises at least one accelerometer and an auxiliary sensor system configured to automatically estimate a bias of the accelerometer of the primary attitude sensor such that the resulting error is removed from an output of the attitude sensor system.

Abstract: A torque sensing device includes a rotating component configured to rotate about an axis of rotation and a first sensor positioned adjacent to the rotating component to sense instantaneous angular position of the rotating component at a first location. A second sensor is positioned adjacent to the rotating component radially inboard of the first sensor to sense instantaneous angular position of the rotating component at a second location. A controller is operably coupled to the first sensor and the second sensor. The controller determines a relative phase shift between a first signal generated by the first sensor and a second signal generated by the second sensor to calculate an output proportional to a torque applied to the rotating component.

Abstract: A strapdown heading sensor includes an elongated housing and a compass module at least partially positioned within an inner cavity of the elongated housing. The compass module is cantilevered within the inner cavity of the elongated housing.

Abstract: A strapdown heading sensor includes an elongated housing and a compass module at least partially positioned within an inner cavity of the elongated housing. The compass module is cantilevered within the inner cavity of the elongated housing.

Abstract: A torque sensing device includes a rotating component configured to rotate about an axis of rotation and a first sensor positioned adjacent to the rotating component to sense instantaneous angular position of the rotating component at a first location. A second sensor is positioned adjacent to the rotating component radially inboard of the first sensor to sense instantaneous angular position of the rotating component at a second location. A controller is operably coupled to the first sensor and the second sensor. The controller determines a relative phase shift between a first signal generated by the first sensor and a second signal generated by the second sensor to calculate an output proportional to a torque applied to the rotating component.

Abstract: A rotational position sensing device includes at least one sensor positioned adjacent a rotating component configured to rotate about an axis of rotation. At least one magnet is positioned at the rotating component such that a magnetic field of the at least one magnet affects the sensor and magnetizes a portion of the rotating component. The at least one sensor is configured to produce an output signal indicative of a magnetic flux, and therefore a position, of the rotating component. A method of sensing a position of a rotating component includes magnetizing a portion of a rotating component with a magnet and measuring a magnetic flux of the rotating component as it rotates about an axis of rotation. An output signal is generated that is indicative of the position of the rotating component.

Abstract: A system is provided for balancing state of charge among plural series connected electrical energy storage units that includes a power converter that selectively couples to an individual storage unit of the a string of electrical energy storage units and transfers energy by bidirectionally between the individual storage unit and the string of storage units.

Abstract: A system is provided for balancing state of charge among plural series connected electrical energy storage units that includes a power converter that selectively couples to an individual storage unit of the a string of electrical energy storage units and bidirectionally transfers energy between the individual storage unit and the string of storage units.

Abstract: A system and method of balancing state of charge among plural series connected electrical energy storage unit is provided. Individual storage units are selectively coupled by semiconductor switches for monitoring and balancing state of charge. When the state of charge of a selected unit is greater than a target state of charge, energy is transferred from the selected unit to the string of storage units, such that the state of charge of the selected unit converges toward the target state of charge. Conversely, when the state of charge of a selected unit is less than a target state of charge, energy is transferred from the string of storage units to the selected unit, such that the state of charge of the selected unit converges toward the target state of charge.

Abstract: A system and method for determining and balancing state of charge among plural series connected electrical energy storage units is provided. State of change of a selected storage unit in a string of storage units is determined by (i) applying a non-dissipative load to the selected storage unit, resulting in an energy transfer between the selected storage unit and the string of electrical energy storage units through the non-dissipative load and (ii) determining the state of charge of the selected unit from voltage and current data of the selected storage unit resulting from the energy transfer. When the state of charge of the selected unit is different than a target state of charge, energy can be transferred between the selected unit and the string of storage units, such that the state of charge of the selected unit converges toward the target state of charge.

Abstract: A device and system for indicating rapid deceleration to warn the operator and/or others of an urgent deceleration condition is provided. The device includes one or more sensors that are responsive to acceleration in the primary direction of vehicle motion. The controller communicates with the one or more sensors, corrects for gravitational effects, and initiates at least one warning indicator when the sensed acceleration exceeds a threshold value and thereby indicates an urgent deceleration condition.

Abstract: A device and method used to indicate vehicle inclination and conditions indicative of a potential rollover is disclosed. The device and method may be embodied in original equipment or in an aftermarket product in a manner so that the driver may easily determine the vehicle inclination. For example, the device and method may be embodied in a mirror assembly mounted in the vehicle. The device and method may also be used to detect the rate of change of inclination to provide a warning of adverse driving conditions. The device and method may also include a compass that indicates a corrected heading of the vehicle.

Abstract: A system and method for determining and balancing state of charge among plural series connected electrical energy storage units is provided. State of change of a selected storage unit in a string of storage units is determined by (i) applying a non-dissipative load to the selected storage unit, resulting in an energy transfer between the selected storage unit and the string of electrical energy storage units through the non-dissipative load and (ii) determining the state of charge of the selected unit from voltage and current data of the selected storage unit resulting from the energy transfer. When the state of charge of the selected unit is different than a target state of charge, energy can be transferred energy between the selected unit and the string of storage units, such that the state of charge of the selected unit converges toward the target state of charge.