Position detection device, position detection method, automated guided vehicle, and sewing device

A position detection device that detects a rotational position of a motor, the position detection device comprising:

• a first sensor group including N (N is a multiple of 3) first magnetic sensors facing a magnet that rotates in synchronization with a rotation shaft of the motor and arranged at predetermined intervals along a rotation direction of the magnet, and a second sensor group including N second magnetic sensors arranged at positions opposite respectively to the N first magnetic sensors across the rotation shaft in a radial direction of the magnet;
• and
• a signal processing device that processes output signals respectively output from the N first magnetic sensors and the N second magnetic sensors, wherein
• the signal processing device executes
• averaging processing of generating N average signals by averaging an output signal of the first magnetic sensor and an output signal of the second magnetic sensor arranged at the position opposite to the first magnetic sensor across the rotation shaft, and
• estimation processing of estimating a rotational position of the motor based on the N average signals.