Abstract: A navigable probe system and method of use is provided. The system may include a handle assembly having a locking mechanism enclosed and a stylus, a cannula, and a tracking device extending from the handle assembly. The stylus may include undercuts for receiving pins of the locking mechanism. A cam of the handle assembly may rotate such that in a first position, the pins of the locking mechanism may be engaged with the undercuts and in a second position, the pins of the locking mechanism may be disengaged from the undercuts releasing the stylus from the locking mechanism. The stylus may be slidably engaged with an inner diameter of the cannula. In some arrangements, the handle assembly may include a quick connect system that in a first position attaches the cannula to the handle assembly and in a second position releases the handle assembly and thus stylus from the cannula.

Abstract: A shovel includes a lower traveling body, an upper turning body turnably mounted on the lower traveling body, a cab provided on the upper turning body, an orientation detector configured to detect the relative relationship between the orientation of the upper turning body and the orientation of the lower traveling body, and an alarm device configured to output an alarm when a backward travel operation is performed while it is detected by the orientation detector that the orientation of the upper turning body and the orientation of the lower traveling body are in a predetermined relationship. The backward travel operation is an operation to cause the lower traveling body to travel in the backward direction of the upper turning body.

Abstract: Processes for controlling the flowrate of and recovering energy from a gas stream in a processing unit are described. One process comprises directing a portion of the gas stream through one or more variable-resistance power-recovery turbines to control the flowrate of the gas stream and generate electric power therefrom; and controlling the pressure and temperature of the gas stream so that the gas exiting the power-recovery turbine remains in the gas phase.

Abstract: This disclosure provides a machine tool adjustment method and system thereof. The machine tool adjustment method includes the following steps: enabling a machine tool to perform a circular test; obtaining a measured error value Em from a measuring instrument, and the measured error value Em is defined by the difference between the actual circular trajectory and the preset circular trajectory during the circular test; determining an error condition of the tool machine from the measured error value Em; determining whether the error condition is less than a predetermined criteria; if not, defining a compensation parameter according to the error condition and enabling the machine tool to perform another circular test according to the set compensation parameter until the error condition is less than the predetermined criteria; and if yes, ending the circular test and the machine tool adjustment is finished.

Abstract: A method includes: acquiring time-series data of a control input and a control output; calculating a variable parameter that minimizes an evaluation function, based on observation values of the control input and the control output; and updating the variable parameter with the calculated variable parameter. The evaluation function includes: a first function part that evaluates an entire error that is a control error of the entire observation period and increases the output value as the entire error increases; and at least one of: a second function part that evaluates a sectional error that is a control error of a particular section in the observation period and increases the output value as the sectional error increases; and a third function part that evaluates an instantaneous error that is a control error of a particular time point in the observation period and increases the output value as the instantaneous error increases.

Abstract: The present disclosure relates a multi-leaf collimator. The multi-leaf collimator may include a plurality of leaf modules. Each leaf module of the plurality of leaf modules may include a leaf configured to shield a portion of beams emitted by a radiation source. The leaf may be movable along a guide rail of the multi-leaf collimator. Each leaf module may also include a drive mechanism including a first drive component and a second drive component. The first drive component and the second drive component may be both connected to the leaf. The first drive component and the second drive component may jointly actuate the leaf to move along the guide rail.

Abstract: A numerical control system diagnoses and maintains a numerical control machine tool by measuring backlash and downloading a backlash correction value to the numerical control machine tool. The system includes a host computer device that downloads a monitor management program to a numerical controller of the numerical control machine tool, collects numerical control information input/output between the numerical controller and a servomotor, analyzes the numerical control information, and diagnoses the numerical control machine tool.

Abstract: An articulated robot includes an arm, an actuator, a storage device, and a control device. The storage device stores the correction parameter for correction accuracy required for each of the multiple work regions, which are segmented as the regions in which work on the work target object is performed in the movable region of the robot arm. When the work is instructed with designation of the target position, the control device acquires, from the storage device, a correction parameter corresponding to a work region to which the designated target position belongs, among the multiple work regions. Then, the control device controls the actuator by correcting the target position using the acquired correction parameter.

Abstract: The present invention is directed to an intelligent dimmer that is capable of “learning” the type of load it is controlling, and adjusts its operating parameters accordingly. The present invention can adaptively drive electrical loads over a wide range of wattages. The intelligent dimmer of the present invention is configured to automatically calibrate itself based on the load current demands of a particular electrical load. The intelligent dimmer of the present invention can also adaptively limit in-rush currents to extend the life expectancy of the solid state switching components used therein.

Abstract: A method for the rapid detection of the linear axis angular error of an NC machine tool, belongs to the technical field of NC machine tool testing. Firstly, the measuring device is mounted on the linear axis. Then, the linear axis moves at three different speeds at a constant speed, and the upper measurement system automatically performs multi-channel acquisition and storage of the motion measurement's point measurement data. Then, based on the same geometric error signal, it is decomposed into the different frequency components, and the measurement angle error is filtered at the different speeds. Finally, the measurement angle errors at the three speeds after filtering are superimposed to complete the rapid measurement of the linear axis angular error of the machine tool. The measurement efficiency is high and data processing capability is strong.

Abstract: Processes for controlling the flowrate of and recovering energy from a gas stream in a processing unit are described. One process comprises directing a portion of the gas stream through one or more variable-resistance power-recovery turbines to control the flowrate of the gas stream and generate electric power therefrom; and controlling the pressure and temperature of the gas stream so that the gas exiting the power-recovery turbine remains in the gas phase.

Abstract: A process for reducing pressure of a vapor stream used for reducing a temperature or pressure in a reactor. A pressure of a vapor stream is reduced with a turbine to provide a lower pressure vapor stream. The vapor stream rotates a turbine wheel within the turbine. The turbine wheel is configured to transmit rotational movement to an electrical generator. Thus, electricity is generated with the turbine. The lower pressure vapor stream is injected into a reactor and reduces a temperature in the reactor or reduces a partial pressure of a hydrocarbon vapor in the reactor.

Abstract: An electronic sensor for counting of fluid transmission cycle with wireless interface is disclosed that reduces or eliminates problems with mechanical counters by an electronic fluid transmission cycle counter that is more accurate, reduces labor, improves time efficiency, and removes human error from reporting the fluid cycle count values. The electronic sensor with wireless interface to count the fluid transmission cycles eliminates the mechanical aspect of current counters the landfill gas industry uses.

Abstract: An example method includes identifying an operating state at which a velocity of a hydraulic actuator configured to operate a movable member of a robot is less than a threshold velocity and an actuator force is less than a threshold force, determining a valve command that corresponds to the operating state, such that the valve command is provided to a valve configured to control flow to and from the hydraulic actuator, and the valve includes a spool movable within a body of the valve, and the valve command causes the spool to move within the body of the valve to a position that induces the operating state, and determining a null bias signal based on the valve command.

Abstract: Systems and methods for facilitating an automatic adjustment of a braking system is provided. In one example, a computer-implemented method can comprise generating, by a system operatively coupled to a processor, a braking curve model based on braking usage pattern data corresponding to one or more vehicles. The computer-implemented method can also comprise adjusting, by the system, a supplemental braking component of the first vehicle based on a simulation of one or more braking components corresponding to the one or more vehicles, wherein the one or more braking components is represented by the braking curve model.

Abstract: A method and a system for reproducing a calibration certificate of an electronic instrument having at least one electronic storage means, the method involving separating the calibration certificate data into a first subset of data, which is calibration specific, and a second subset of data, which is document descriptive; defining a set of meta data about the second subset of data; storing the first subset of data and the set of meta data in the instrument's electronic storage means; storing the second subset of data in a computing device separated from the electronic instrument; and reproducing the calibration certificate by uploading the first subset of data and the set of meta data to the computing device and reconstructing the calibration certificate from the uploaded first subset of data set of meta data and the second subset of data.

Abstract: A navigable probe system and method of use is provided. The system may include a handle assembly having a locking mechanism enclosed and a stylus, a cannula, and a tracking device extending from the handle assembly. The stylus may include undercuts for receiving pins of the locking mechanism. A cam of the handle assembly may rotate such that in a first position, the pins of the locking mechanism may be engaged with the undercuts and in a second position, the pins of the locking mechanism may be disengaged from the undercuts releasing the stylus from the locking mechanism. The stylus may be slidably engaged with an inner diameter of the cannula. In some arrangements, the handle assembly may include a quick connect system that in a first position attaches the cannula to the handle assembly and in a second position releases the handle assembly and thus stylus from the cannula.

Abstract: A drive control apparatus in which the target torque which is a target value of an output torque of the prime mover for driving a vehicle, is calculated, and the output torque control is performed so that the output torque of the prime mover coincides with the target torque, is provided. An estimated output torque which is an estimated value of the actual output torque of the prime mover, is calculated, and the torque difference accumulated value which approximates a time-integration value of a torque difference between the target torque and the estimated output torque, is calculated. It is determined that an abnormality has occurred in the output torque control when the torque difference accumulated value exceeds a determination threshold value which is set to a constant value.

Abstract: A compression punch for a rotary press, with a shaft, a punch head disposed at one shaft end and a compression zone disposed at the other shaft end, wherein the punch head features an upper mirror surface, an outer cylinder surface and a curved transition zone between the mirror surface and the cylinder surface, wherein the mirror surface and the transition zone form a three-dimensional surface, whose course in at least one radial direction can be described by a mathematical function whose second derivative is continuous.

Abstract: A test body is provided for determining one or more rotation errors of a rotating apparatus with respect to one or more degrees of freedom of movement, in which a real rotating movement of the rotating apparatus differs from an ideal rotating movement. The test body includes a holder which, together with a part of the rotating apparatus, can be rotated about an axis of rotation. The holder can be configured to arrange or fasten the test body with respect to the axis of rotation about which the test body can be rotated for the purpose of determining the rotation error(s). One or more test elements are rigidly connected to the holder or are formed on the holder, and each of the test elements is used to determine a rotation error with respect to one or more of the degrees of freedom of movement.

Abstract: A calibrating apparatus of a tire testing machine of the present invention calibrates force components along a lateral direction of a load cell on a tire testing machine provided with a rotary drum and the load cell mounted to a shaft portion of the rotary drum and capable of measuring force applied to the rotary drum, and has a hook member hooked on an outer peripheral edge of the rotary drum, a linear body, one end side of which is connected to the hook member, a load applying member connected to the other end side of the linear body and capable of generating a reference load toward a downward direction, and a pulley device around which the linear body is wound to convert the downward force by the load applying member into an upward force on one end side of the linear body.

Abstract: A tire-based system and method for adapting the calculation of temperature-sensitive tire characteristics includes one or more tire-mounted temperature sensors mounted to a vehicle tire for measuring a tire temperature at a tire radially outward surface; an algorithmic model adapting one or more temperature-sensitive tire characteristics by the measured tire surface temperature; and vehicle controls using the temperature-sensitive tire characteristics adapted by the tire surface temperature in one or more vehicle control commands.

Abstract: A system and method of predicting motor failure based on relationships of motor pair characteristics, such as temperatures. A motor pair detection module receives temperatures for each motor of a motor pair over a predetermined window. The motor pair detection module determines whether at least one of the temperatures of the first motor and the second motor exceeds a temperature threshold during the predetermined time window. The motor pair detection module further determines whether the temperature of the first motor differed from the temperature of the second motor by at least a difference threshold for at least a percentage threshold of the predetermined time window. Based on the determinations, the motor pair temperature outputs an alarm signal to indicate a potential impending failure of one of the motors of the motor pair.

Abstract: When engaged, an articulation controller automatically adjusts an angle of articulation between a front frame and a rear frame of a motor grader based on a steering angle of the front wheels. If a groundspeed of the motor grader exceeds a threshold groundspeed, the articulation controller enters a mode that only allows decreasing the angle of articulation of the motor grader. When the angle of articulation reaches zero, the articulation controller disengages until the groundspeed is reduced below the threshold groundspeed.

Abstract: A measuring system including a sensor positioned to a belt to measure an oscillation or vibration of the belt based at least in part on a trigger threshold. Also, the measuring system may include a diagnostic tool coupled the sensor to receive a plurality of measurements of the oscillation or vibration of the belt, wherein the diagnostic tool may determine a tension of the belt based at least in part on an average of the plurality of measurements of the oscillation or vibration of the belt.

Abstract: In accordance with an embodiment of the present invention, a method of forming an electronic device includes forming a first opening and a second opening in a workpiece. The first opening is deeper than the second opening. The method further includes forming a fill material within the first opening to form part of a through via and forming the fill material within the second opening.

Abstract: A process modeling technique uses a single statistical model developed from historical data for a typical process and uses this model to perform quality prediction or fault detection for various different process states of a process. The modeling technique determines means (and possibly standard deviations) of process parameters for each of a set of product grades, throughputs, etc., compares on-line process parameter measurements to these means and uses these comparisons in a single process model to perform quality prediction or fault detection across the various states of the process. In this manner, a single process model can be used to perform quality prediction or fault detection while the process is operating in any of the defined process stages or states.

Abstract: A bicycle derailleur adjusting apparatus for adjusting a bicycle derailleur includes a controller. The bicycle derailleur includes a base member adapted to be mounted to a bicycle, a movable member, a linkage coupled between the base member and the movable member, and an actuator configured to move the movable member of the bicycle derailleur among a plurality of derailleur positions. The controller is configured to control the actuator based on a travel value indicative of a travel distance of the movable member between adjacent derailleur positions to update the derailleur positions of the movable member.

Abstract: A calibration method for calibration a tool center point for a robot manipulator includes the steps of: driving the tool to move above one of the inclined surfaces; defining a preset coordinate system TG; rotating the TCP relative to the UG-axis by about 180 degrees, calculating the value of ?w; updating the position parameters of the preset TCP, defining a new preset coordinate system TG?; rotating the TCP relative to the UG?-axis by about 90 degrees, calculating the value of ?v; updating the position parameters of the new preset TCP, defining a new preset coordinate system TG?; driving the tool to move above a planar horizontal surface; rotating the TCP relative to a axis by about 30 degrees, calculating the value of ?u; repeating the aforementioned steps until the deviation ?P (?w, ?v, ?u) is less than or equal to a maximum allowable deviation of the robot manipulator.

Abstract: Method for determining a twist structure in the surface roughness of a workpiece which is cylindrical at least in part includes that multiple sampling segments which extend in the axial direction of the workpiece and which are mutually spaced apart in the circumferential direction are carried out in a surface region of interest on the workpiece, and the value of at least one parameter of the twist structure is determined based on the measured values obtained using the sampling segments. An estimated value of at least one parameter of the twist structure is determined based on the measured values associated with a first sampling segment, the estimated value being corrected based on the measured values associated with at least one second sampling segment.

Abstract: In order to set an inspection area in an inspection apparatus for inspecting a board, a plurality of measurement areas are set on a board, and then reference data and measurement data of at least one adjacent measurement area that is adjacent to a target measurement area for inspecting a measurement target, among the measurement areas, are acquired. Thereafter, at least one feature object is extracted from the adjacent measurement area. Then, a distortion degree is acquired by comparing reference data and measurement data corresponding to the feature object with each other, and thereafter the distortion degree is compensated for, to set an inspection area in the target measurement area. Thus, a conversion relation between the reference data and the measurement data may be correctly acquired, and an inspection area, in which distortion is compensated for, may be correctly set.

Abstract: A photoacoustic detector wherein control circuits compensate for long term variations of components therein including a light source and sensing microphones. The control circuits intermittently energize the source to evaluate changes in at least source resistance. The control circuits intermittently energize an acoustic generator to evaluate changes in one or more generator responsive microphones.

Abstract: Systems and methods for determining a bias-corrected value of at least one component of a gravity gradient tensor using a gravity gradiometer and a measurement bias of the gravity gradiometer wherein the measurement bias varies with time, by taking at least three measurements with the gravity gradiometer positioned in at least two orientations. Any gravity gradiometer can be used, including a Cross-Component Gravity Gradiometer (CCGG), an Orthogonal Quadrupole Responder (OQR), an In-Line Responder (ILR), a Diagonal-Component Gravity Gradiometer, or a Multi-Component Gravity Gradiometer (MCGG).

Abstract: Calibration equipment for calibrating multiple test stations in a test system is provided. Each test station may include a test unit, a test fixture, and a radio-frequency (RF) cable that connects the test unit to the test fixture. A control test setup may be used to calibrate uplink and downlink characteristics associated with each test station (e.g., to determine path loss associated with the RF cable and test fixture and variations associated with the test unit). The control test setup may calibrate each test station at desired frequencies to generate a test station error (offset) table. The test unit of each test station may be individually configured based on the test station error table so that offset is minimized among the different stations and so that the test stations may reliably measure hundreds or thousands of wireless electronic devices during product testing.

Abstract: A method and apparatus for carrying out auto-calibration of one or more piezoelectric elements in a force transducer assembly of a vehicle wheel balancing system. Output electrical signals from the piezoelectric transducers in response to application of a known imbalance force are measured and recorded. Subsequently, during an auto-calibration procedure, a known input signal is selectively applied to at least one piezoelectric element in the force transducer assembly, and at least one output electrical signal is received from the force transducer assembly. The obtained auto-calibration output signals are evaluated with respect to the output signals obtained from a previous auto-calibration, and compensation values are derived there from for application to subsequent output signals obtained during imbalance measurements.

Abstract: The present invention provides a method and apparatus for testing a valve control system in an aircraft fuel supply system having a plurality of control valves, wherein the control system includes a processor adapted to receive feedback signals from each of the plurality of control valves, the method comprising the steps of: connecting a test device to the control system such that the test device is connected for signal transmission to the processor; outputting a signal to the processor simulating a feedback signal from at least one of the control valves; detecting a control signal which is output by the processor to the at least one of the control valves; and identifying the detected control signal which is output by the processor to the control valve.

Abstract: Methods and systems are for controlling movement of at least one propulsion unit on a marine vessel. The method comprises plotting a first plurality of points representing a first surface of a first propulsion unit and plotting a second plurality of points representing a second surface. The method further comprises limiting movement of at least the first propulsion unit such that the first surface does not come within a predetermined distance of the second surface during said movement.

Abstract: In a numerically controlled machine tool which has a linear feed axis and a rotational feed axis and in which a main spindle and a table are movable relative to each other, a position error and an attitude error produced by an operation of a linear feed axis and a rotational feed axis are measured at a plurality of measurement points set within a movable range of the linear feed axis and the rotational feed axis, and the position error and the attitude error thus measured are stored as an error map in correspondence to a position of the linear feed axis and a rotation angle of the rotational feed axis.

Abstract: Method for measuring the shape of a workpiece includes a measuring sensor used to find measured values that represent the shape of a workpiece. The shape of the workpiece is determined by an iterative method using the measured values. The shape of the workpiece is determined during machining. The determining of the shape during machining is particularly suited for determining the shape during grinding. The shape determined may be the shape of a pin, especially a crankpin for a crankshaft.

Abstract: The present invention models dynamic behavior of flight vehicles for simulation, analysis, and design. The present invention allows a user to define the complexity of a flight vehicle model, and such models may be simple rigid body models, models of medium complexity, or very complex models including high order dynamics comprising hundreds of structural flexibility modes and variables related to aero-elasticity, fuel sloshing, various types of effectors, tail-wags-dog dynamics, complex actuator models, load-torque feedback, wind gusts, and other parameters impacting flight vehicles. The present invention accommodates and analyzes multiple vehicle and actuator concepts and configurations as defined in flight vehicle input data, which specifies flight vehicle parameters at a steady-state condition for modeling flight vehicle response to dynamic forces and flight control commands with respect to steady state operation.

Abstract: There is provided a control device configured to control a drive system including a motor and a driven object. The control device includes a controller configured to compute an operation amount, to measure a control amount of the controlled object, to input a measurement signal of the control amount to an inverse model of a model indicating input-output characteristics of the controlled object, and to generate a differential signal between an output of the inverse model and the operation amount; and a filter configured to filter the generated differential signal, and which has frequency characteristics of attenuating a vibrational component which is developed due to mechanical characteristics of the controlled object, from the differential signal. The controller is configured to make a judgment of whether or not a defect has occurred in the controlled object, based on an output of the filter.

Abstract: A correction method in which characteristic curves and/or correction values are produced, by way of which the drive current for one or more electrically activated hydraulic values operated in an analog fashion is measured during a pressure regulation in such a way that, during the operation of an anti-lock regulation, one or a respective characteristic curve is first prescribed and then the prescribed characteristic curve is corrected, particularly in a learning process, wherein, after a pressure build-up phase, the current pressure model value (Pmod) is compared to and/or analyzed using a model locking pressure level (Pmax).

Abstract: A method of calibrating a mechanical instrument assembly includes reading a memory device coupled with a mechanical testing instrument, the mechanical testing instrument having one or more mechanical characteristics with values unique to the mechanical testing instrument, and reading includes reading of one or more calibration values based on the one or more mechanical characteristic values. The method further includes calibrating the mechanical instrument assembly according to the one or more calibration values. The mechanical testing instrument is coupled with the mechanical instrument assembly.

Abstract: A measurement instrument having a processor, a first sensor and a second sensor. The processor is adapted to output a measurement signal embodying a measurement of a physical quantity. The first sensor and second sensor are connected to the processor and are operable to generate respectively first and second measurements of the physical quantity. The processor defines a first measurement range within which the measurement signal is dependent on the first measurement and not the second measurement. The processor defines a second measurement range within which the measurement signal is dependent on the second measurement and not the first measurement. The first and second ranges meet at a predetermined transition. The first and second measurements are different at the transition and the measurement embodied in the measurement signal crosses the transition without an abrupt change.

Abstract: An electronic device can include an inertial measurement unit (IMU) operative to monitor the movement of the electronic device. The IMU used in the device can be inaccurate due to the manufacturing process used to construct the IMU and to incorporate the IMU in the electronic device. To correct the IMU output, the electronic device in which the IMU is incorporated can be placed in a testing apparatus that moves the device to known orientations. The IMU output at the known orientations can be compared to an expected true IMU output, and correction factors (e.g., sensitivity and offset matrices) can be calculated. The correction factors can be stored in the device, and applied to the IMU output to provide a true output. The testing apparatus can include a fixture placed in a gimbal movable around three axes.

Abstract: An improved method for calibration of dynamic motion sensors. In one aspect, the method comprises sending a low frequency driving signal to an exciter to generate a harmonic movement in a shaker table, using an optical position sensor to produce an output representative of position, computing the acceleration of the shaker table and a dynamic motion sensor under test (SUT), and comparing the output of the SUT with the instantaneous acceleration of the shaker table at different frequencies sufficient to define the performance characteristics of the SUT within a selected frequency range, among other things. In another aspect, the method comprises calibration of a dynamic motion SUT by simultaneous direct measurement of position and time. In another aspect, the optical position sensor has an electrical output representative of position for attaining a desired degree of positional accuracy.

Abstract: The computer implemented method, system or computer program product comprises collecting magnetometer data from the device; and calculating a center of a shape of the magnetometer data as a result of minimization. The minimization of calculating the center of the shape further comprises calculating a plurality of running sums of the magnetometer data; storing the plurality of running sums; storing a count of the number of terms in each of the running sums; and calculating the center of the shape and setting the estimated magnetometer bias to the center of the shape. The radius of the sphere is calculated to ensure accuracy in the estimator of the magnetometer bias.

Abstract: A method for self-adjustment of a triaxial acceleration sensor during operation includes: calibrating the sensor; checking the self-adjustment for an interfering acceleration, with the aid of a measurement equation and estimated values for sensitivity and offset; repeating the adjustment if an interfering acceleration is recognized; and accepting the estimated values for sensitivity and offset as calibration values if an interfering acceleration is not recognized. The step of checking the self-adjustment includes: estimating sensitivity and/or offset and the variance thereof; determining an innovation as the difference between a measured value of the measurement equation and an estimated value of the measurement equation; testing the innovation for a normal distribution; and recognizing the interfering acceleration in the event of a deviation from the normal distribution.

Abstract: An apparatus and method improves the fault tolerance of a rocket or missile guidance system which includes a resonant sensor. When improper initialization is detected, the resonant sensor is reinitialized, repeatedly if necessary, until normal operation is achieved. Improper initialization is detected by comparing data from the guidance system with pre-specified physical limits to roll, pitch, yaw, and/or other features of the flight scenario. Embodiments can also detect a fault condition due to an error signal from a “Built-in-Test” (BIT) module. The initialization sequence initiated by the invention can be identical to the power-on sequence, or it can be a separate, reinitiating sequence. Subsequent resets are initiated as needed, for example until the burn of the rocket fuel and the associated vibrations have ceased and the resonant sensor has been successfully initialized.

Abstract: In a rotation angle positioning device 6 including: a rotation angle detection device 7 which has a detection target ring 8 and an angle detection sensor 9; and a rotating-shaft driving device 10 rotating a rotating shaft so as to cause a rotation angle to become a given command value ? for rotation angle, there are provided: an error pattern storage unit 11a storing a tooth-to-tooth period error pattern F made up of errors between detected rotation angles by the angle detection sensor 9 and actual rotation angles, corresponding to respective correction dividing points of an arbitrary tooth-to-tooth period in the detection target ring 8; and a command value correction unit 11b correcting the command value ? for rotation angle based on the tooth-to-tooth period error pattern F to find a corrected command value ?2 for rotation angle.