Linear motor system

A linear motor system comprising:

• a stator including a plurality of coils that are arranged in a line;
• a mover including a permanent magnet disposed opposite to the plurality of coils;
• a switcher that performs:
• (i) selecting, from among the plurality of coils, one or more coils each including a region that extends across opposite ends in an arrangement direction and faces the permanent magnet as one or more power supply target coils that serve as power supply targets;
• and (ii) switching the one or more power supply target coils in response to a movement of the permanent magnet;
• and
• a plurality of control units provided in one-to-one correspondence with the plurality of coils,
• wherein each of the plurality of control units includes:
• a position deviation calculation unit that calculates a position deviation that is a difference between an instructed position of the mover and an actual position of the mover obtained by subtracting the actual positon of the mover from the instructed position of the mover;
• a speed control unit that generates a torque instruction based on the position deviation;
• and
• a current control unit that supplies power to the one or more power supply target coils based on the torque instruction, and
• when one or more control units out of the plurality of control units that correspond to the one or more power supply target coils are defined as one or more power supply target control units:
• the one or more power supply target control units immediately before the switching transmit Δθ (t0−td), which is the position deviation at time t=t0−td, to one or more control units that serve as new one or more power supply target control units immediately after the switching;
• and
• the one or more control units that serve as the new one or more power supply target control units immediately after the switching:
• (i) receive the position deviation Δθ (t0−td) at time t=t0;
• (ii) calculate Δθ (t0), which is the position deviation at time t=t0, based on Δθ (t0) =Δθ (t0−td) +A — B, where A is a difference between the instructed position at time t=t0 and the instructed position at time t=t0 — td, and B is a difference between the actual position at time t=t0 and the actual position at time t=t0 — td;
• and
• (iii) supply power to the one or more power supply target coils by using the position deviation Δθ (t0) when the new one or more power supply target control units immediately after the switching serve as the one or more power supply target control units.