Okuma Corporation

Yoshimasa Egi

In a position control device that controls a rotational speed and a rotational angle of a three-phase synchronous motor by calculating a d-axis current command value and a q-axis current command value based on a position command and causing a inverter to adjust current values of respective phases of the three-phase synchronous motor, a processor calculates a d-axis additional current value to be added to the d-axis current command value. The d-axis additional current value oscillates in such a manner that the polarity changes according to an electrical angle and crosses a zero level with an inclination whose polarity is opposite the polarity of a first q-axis current command value at a zero-cross electrical angle. As a result, positional deviation ripples caused by dead time can be suppressed.

Position control device

In a control apparatus which uses a CPU which does not have hardware for memory protection, a function is realized to detect unauthorized writing from a non-safety-related unit program in units of bits, for a safety-related unit data area of a RAM, a safety-related unit register area of an external integrated circuit, and a built-in peripheral I/O register of the CPU. A memory access monitoring unit requests an interrupt process upon detection of a write access of the safety-related unit program permitted to access a safety-related unit region. The interrupt process realizes a function to detect write access from a non-safety-related unit program area by using a program counter of a write access origin retracted to a stack area to judge whether the write access origin is a safety-related unit program or the non-safety-related unit program area, and judge, in units of bits, whether or not there is a change to a safety-related unit region.

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Aichi, Japan

Yoshimasa Egi