Answer: (D) AC or DC motor with feedback device to detect the displacement of the end actuator of the machine tool.
Question Answer Reason Analysis:
Closed-loop control CNC machine tool refers to the installation of linear displacement detection device on the moving parts of the machine tool, directly detecting the actual displacement of the worktable, feeding the measured actual displacement value back to the CNC device, comparing it with the input command displacement value, controlling the machine tool with the difference, so that the moving parts move according to the actual required displacement, and finally realize the precise movement and positioning of the moving parts.
The advantages of closed-loop control CNC machine tools are high control accuracy and fast speed, but debugging and maintenance are more complicated, and the key is the stability of the system, so sufficient attention must be paid to stability when designing.