Numerical controller with machining time prediction unit and machining error prediction unit

A numerical controller for drivingly controlling a machine tool which machines a workpiece based on a machining program, the numerical controller comprising:

• a designation unit for designating speed data for giving a machining speed and precision data for giving a machining precision;
• a simulation unit which determines a command position point sequence and a servo position point sequence for each processing period by simulating a program analysis process, an interpolation process, a post-interpolation acceleration/deceleration process, and a servo operation, using the speed data and the precision data designated for the machining program by the designation unit;
• a machining time prediction unit which determines a predicted machining time during which the workpiece will be machined in the simulation unit;
• and
• a machining error prediction unit which determines a predicted machining error caused when the workpiece will be machined using the command position point sequence and the servo position point sequence determined by the simulation unit.