Nidec Corporation

Nidec Instruments Corporation

Shota Ishigami

Atsushi Fujita

Tomohiro Fukumura

Tomohisa Tokunaga

Toru Kitanoya

Yutaka Saito

One aspect of an angle detection device of the present invention includes: three magnetic sensors that detect a change in magnetic flux due to rotation of a rotation shaft; and a signal processing unit that processes signals output from the three magnetic sensors. The signal processing unit acquires sensor signals output from three magnetic sensors, extracts an intersection point at which two sensor signals among the three sensor signals intersect with each other and a zero-cross point at which each of the three sensor signals intersect with a reference signal level, generates a linear function θ(Δx) representing a straight line connecting the intersection point adjacent to each other and the zero-cross point, calculates a deviation between a mechanical angle θ calculated based on the linear function θ(Δx) for a plurality of points on the straight line and a mechanical angle θe acquired from an encoder installed on a rotation shaft as a first angle error, and generates a first angle error function for calculating a first angle error corresponding to an arbitrary point on the straight line based on the first angle error calculated for the plurality of points on the straight line.

Angle detection method and angle detection device

A method of position estimation including: a signal detection step in which N (where N is an integer of 3 or more) sensors each detect a magnetic field which is in accordance with a position of a mover and output a detection signal as an electrical signal, the detection signals being displaced in phase by an angle obtained by dividing 360 degrees by N; a crossing detection step in which a crossing detection section sequentially detects a crossing at which each detection signal having been output through the signal detection step crosses another; a subdivision detection step in which a subdivision detection section detects a portion of the detection signal that connects from a crossing to another crossing which is adjacent to that crossing, as one or more subdivision signals; and a line segment joining step in which a line segment joining section sequentially joins the subdivision signals and estimates the position of the mover based on the plural subdivision signals having been joined, to generate an estimated position value signal.

Position estimation method and position control device

A position estimation device acquires detection values of magnetic field strength at three or more locations of a rotor in a range where a rotor angle is less than one rotation. A section is selected based on a detection value of the magnetic field strength from predetermined sections for a pole pair number of the rotor. A feature amount calculator is provided to calculate feature amounts of a waveform of the magnetic field strength based on a combination of the detection values of the magnetic field strength according to the section selected. An estimator is provided to determine, for each segment associated with the section selected, whether or not a magnitude relationship of the feature amounts learned in advance coincides with a magnitude relationship of the feature amounts calculated, and estimating, as a rotation position of the rotor, the pole pair number associated with the segment having the same magnitude relationship.

Position estimation device and position estimation method

A position estimation method of the present disclosure includes: acquiring learning data from a storage medium that stores the learning data including a sequence of a plurality of measurement values which define a waveform characteristic of a first electrical signal output from a sensor device when a rotor R is rotating; acquiring a sequence of a plurality of detection values which define a waveform characteristic of a second electrical signal output from the sensor device when the rotor starts rotating from a stopped state; and performing matching between an increase/decrease pattern of the sequence of the plurality of measurement values and an increase/decrease pattern of the sequence of the plurality of detection values to estimate a relationship between a rotation position of the rotor when the first electrical signal is output and a rotation position of the rotor when the second electrical signal is output.

Position estimation method, position estimation device, and motor module for estimating position of rotor in motor

In one implementation, a motor module according to the present invention includes: a motor driving circuitto drive a motor M; and a position estimation deviceto output an estimated position signal of a rotor R of the motor M. It also includes: a motor control circuitto supply a command voltage value to the motor driving circuitin response to a pulse signal; and a variable step-size memorystoring variable step-size information, which defines an amount of displacement of the rotor R per pulse of the pulse signal. The estimated position signal is an analog or digital signal. Upon receiving a pulse signal, the motor control circuitdetermines the command voltage value based on an estimated position value of the rotor R acquired from the position estimation deviceand the variable step-size information read from the variable step-size memory. The motor driving circuitchanges the position of the rotor R based on the command voltage value.

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Kyoto, Japan

Shota Ishigami