# US 10,312,837 B2 · Information processing apparatus, and recording medium storing computer program > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,312,837 B2 - Document ID: US10312837B2 - Status: Granted - Kind: B2 - Application number: 15/495,833 - Filed: 2017-04-24 - Published: 2017-11-02 - Granted: 2019-06-04 - Earliest claimed: 2016-05-02 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Masahiko Mizoguchi; Tadayoshi Nakayama; Toru Aida - Web page: https://patentgrep.com/patent/US10312837B2 ## CPC - H02P 6/08: Arrangements for controlling the speed or torque of a single motor (H02P6/10, H02P6/28 take precedence) - G01D 5/24476: {Signal processing (G01D5/2448 - G01D5/24495 take precedence)} - G01D 5/34: the beams of light being detected by photocells - G01D 5/34707: {Scales; Discs, e.g. fixation, fabrication, compensation} - G01D 5/3473: {Circular or rotary encoders} - G06F 17/00: Digital computing or data processing equipment or methods, specially adapted for specific functions (information retrieval, database structures or file system structures therefor G06F16/00) - H02P 29/50: Reduction of harmonics - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract An information processing apparatus includes an acquisition unit configured to acquire a first phase signal and a second phase signal that are acquired by measuring a rotation of a moving object, and a calculation unit configured to calculate a rotational angle by an iterative calculation so as to satisfy a relational expression bearing an arctangent. The relational expression bearing the arctangent uses a first cosine wave and a second cosine wave at a higher harmonic of the first cosine wave for the first phase signal, and a first sine wave and a second sine wave at a higher harmonic of the first sine wave for the second phase signal. The first phase signal and the second phase signal may, for example, be analog signals having a wave shape. ## Claims ### Claim 1 An information processing apparatus for supplying a rotational angle of a moving object to a controller of the moving object, comprising: an encoder configured to acquire a first phase signal and a second phase signal that are acquired by measuring a rotation of the moving object; and a calculation unit comprising at least one processor configured to calculate the rotational angle of the moving object by an iterative calculation so as to satisfy a relational expression bearing an arctangent, the relational expression bearing the arctangent using addition or subtraction including a first cosine wave and a second cosine wave at a higher harmonic of the first cosine wave for the first phase signal, and addition or subtraction a first sine wave and a second sine wave at a higher harmonic of the first sine wave for the second phase signal. ### Claim 2 (depends on 1) The information processing apparatus according to claim 1, wherein at least one of the first phase signal and the second phase signal is at least one of an analog signal and a signal having a wave shape. ### Claim 3 (depends on 1) The information processing apparatus according to claim 1, further comprising a control unit configured to control a device based on the calculated rotation angle. ### Claim 4 (depends on 1) The information processing apparatus according to claim 1, wherein the iterative calculation is a CORDIC calculation. ### Claim 5 (depends on 1) The information processing apparatus according to claim 1, wherein initial values of the first sine wave and the second sine wave are zero in the iterative calculation. ### Claim 6 (depends on 1) The information processing apparatus according to claim 1, wherein the calculation unit includes a plurality of calculation circuits configured to carry out respective calculations included in the iterative calculation, and wherein the calculation circuits are connected together as a pipeline. ### Claim 7 (depends on 1) The information processing apparatus according to claim 1, wherein the calculation unit includes a plurality of calculation circuits configured to carry out respective calculations included in the iterative calculation, and wherein the calculation circuits are connected together recursively. ### Claim 8 (depends on 1) The information processing apparatus according to claim 1, further comprising an output unit configured to output a signal in which at least any one component of the second cosine wave and the second sine wave is removed. ### Claim 9 (depends on 1) The information processing apparatus according to claim 1, further comprising a control unit configured to control a rotation of a motor that controls a position of the moving object based on a result of the calculation by the calculation unit. ### Claim 10 (depends on 4) The information processing apparatus according to claim 4, wherein the calculation unit includes a correction unit configured to correct an absolute value of coordinate data in the CORDIC calculation. ### Claim 11 (depends on 8) The information processing apparatus according to claim 8, wherein the output unit outputs the signal as an encoder signal indicating a positional displacement of the moving object. ### Claim 12 A recording medium storing a program that upon execution by a computer causes the computer to function as an information processing apparatus for supplying a rotational angle of a moving object to a controller of the moving object, the information processing apparatus comprising: an acquisition unit configured to acquire a first phase signal and a second phase signal that are acquired by an encoder measuring a rotation of the moving object; and a calculation unit configured to calculate the rotational angle of the moving object by an iterative calculation so as to satisfy a relational expression bearing an arctangent, the relational expression bearing the arctangent using addition or subtraction including a first cosine wave and a second cosine wave at a higher harmonic of the first cosine wave for the first phase signal, and addition or subtraction including a first sine wave and a second sine wave at a higher harmonic of the first sine wave for the second phase signal.