An angular rotation sensor system constituted of: an input shaft target and an output shaft target each comprising a plurality of members parallel to a longitudinal axis of an input shaft or output shaft; a gear target with an angular velocity exhibiting a predetermined ratio with an angular velocity of the input shaft, the gear target comprising a plurality of members, each extending away from the input shaft and orthogonal to a plane which is parallel to the longitudinal axis of the input shaft; and a control circuitry arranged to: determine an angular position of the input shaft responsive to a sensed angular rotation of the input shaft target and a sensed angular rotation of the gear target; and determine the amount of torque applied to the input shaft responsive to the sensed angular rotation of the input shaft target and a sensed angular rotation of the output shaft target.

An angular rotation sensor system constituted of: an input shaft target and an output shaft target each comprising a plurality of members parallel to a longitudinal axis of an input shaft or output shaft; a gear target with an angular velocity exhibiting a predetermined ratio with an angular velocity of the input shaft, the gear target comprising a plurality of members, each extending away from the input shaft and orthogonal to a plane which is parallel to the longitudinal axis of the input shaft; and a control circuitry arranged to: determine an angular position of the input shaft responsive to a sensed angular rotation of the input shaft target and a sensed angular rotation of the gear target; and determine the amount of torque applied to the input shaft responsive to the sensed angular rotation of the input shaft target and a sensed angular rotation of the output shaft target.

A method for determining a cogging torque may include applying a substantially constant rotation torque to an output shaft of a motor without electrically energizing the motor; detecting, an angle of rotation of the output shaft of the motor at each of a plurality of angles of rotation; calculating an angular acceleration of the motor at each of the plurality of angles of rotation by second order differentiating the angle of rotation; calculating a measured torque value at each of the plurality of angles of rotation by multiplying the angular acceleration by a moment of inertia of a rotor in the motor; obtaining a measured torque waveform of the measured torque value at each of the plurality of angles of rotation as a function of the plurality of angles of rotation; and calculating a cogging torque waveform based on a frequency of the measured torque waveform.

A method for determining a cogging torque may include applying a substantially constant rotation torque to an output shaft of a motor without electrically energizing the motor; detecting, an angle of rotation of the output shaft of the motor at each of a plurality of angles of rotation; calculating an angular acceleration of the motor at each of the plurality of angles of rotation by second order differentiating the angle of rotation; calculating a measured torque value at each of the plurality of angles of rotation by multiplying the angular acceleration by a moment of inertia of a rotor in the motor; obtaining a measured torque waveform of the measured torque value at each of the plurality of angles of rotation as a function of the plurality of angles of rotation; and calculating a cogging torque waveform based on a frequency of the measured torque waveform.

The described techniques are directed to inductive torque sensors that implement independent target coil and pickup coil systems. By utilizing the various principles of inductive angle sensors, and as a result of the specific physical arrangement of target coils, the inductive torque sensor may independently obtain a rotational position (i.e., mechanical angle) of the rotatable input shaft via one pickup coil system, and a rotational position (i.e., mechanical angle) of the rotatable output shaft via another pickup coil system. Combiner circuitry is also provided to calculate the torsion angle using the signals induced in each of two separate pickup coil systems. By using different k-fold symmetry periodicities in the target coils with respect to the coil configurations, the inductive torque sensor advantageously reduces or eliminates mutual coupling between the different target coil systems and provide robustness to stray or external electromagnetic fields.

The described techniques are directed to inductive torque sensors that implement independent target coil and pickup coil systems. By utilizing the various principles of inductive angle sensors, and as a result of the specific physical arrangement of target coils, the inductive torque sensor may independently obtain a rotational position (i.e., mechanical angle) of the rotatable input shaft via one pickup coil system, and a rotational position (i.e., mechanical angle) of the rotatable output shaft via another pickup coil system. Combiner circuitry is also provided to calculate the torsion angle using the signals induced in each of two separate pickup coil systems. By using different k-fold symmetry periodicities in the target coils with respect to the coil configurations, the inductive torque sensor advantageously reduces or eliminates mutual coupling between the different target coil systems and provide robustness to stray or external electromagnetic fields.

An engine torque estimating system includes: an engine; a crank angle sensor installed for a crankshaft of an engine; an acquiring circuit for acquiring, from the crank angle sensor, a chronological waveform in which amplitude changes based on a rotational speed of the crankshaft; a generating circuit for generating input data to a mathematical model based on information of the amplitude of the chronological waveform; a calculating circuit for calculating an estimated value of engine torque by giving the generated input data to the mathematical model; and a control circuit for controlling the engine based on the estimated value of engine torque.

An engine torque estimating system includes: an engine; a crank angle sensor installed for a crankshaft of an engine; an acquiring circuit for acquiring, from the crank angle sensor, a chronological waveform in which amplitude changes based on a rotational speed of the crankshaft; a generating circuit for generating input data to a mathematical model based on information of the amplitude of the chronological waveform; a calculating circuit for calculating an estimated value of engine torque by giving the generated input data to the mathematical model; and a control circuit for controlling the engine based on the estimated value of engine torque.

Methods and apparatus for identifying downhole dynamics in a drilling system are provided. Acceleration-detecting sensors are mounted at multiple locations near to a drill bit, such as at a drill collar. The sensors may be spaced 90? apart along a circumference of the drill collar. The sensors detect acceleration measurements in a plane orthogonal to the drill string's axis of rotation, with respect to a first reference frame that moves with the drill string. The acceleration measurements are received by a processor and processed to determine rotational and revolution positions of the drill string within the wellbore with respect to a static reference frame. Whirl dynamics may, in particular, be determined based on the results in real time.

A device and principal method for measuring flow through a pipe for liquid and compressed gas. In an embodiment, the device is comprised of eccentric disk, rotation sensor, torque/stress sensor, coil spring, track rod, supports, and a digital processor. The processor determines the flow based on measured torque/stress, rotation, and other pre-determined parameters and relationship equations. The processor also provides data communication with other controllers and human-machine interface devices. In one simplified option, the arm may be fixed in one position and the rotation sensor is eliminated. In another simplified option, the torque sensor is removed. The compression of coil spring is measured by the rotation sensor. The torque is then determined using the coil spring performance and measured coil spring compression. The torque based flowmeter can be implemented to any industrial corrosive liquids, water, and gas with or without suspended solids.