A numerical control device for a machine tool which causes a tool to move along a movement path decided according to a machining program, the numerical control device including: a limit setting storage unit in which limit values of a plurality of parameters related to movement of the tool are set; a limit velocity calculation unit which calculates a plurality of limit velocities, which respectively correspond to the limit values at each position of the movement path; a feedrate determination unit which defines a minimum value among an ideal velocity of the tool and the plurality of limit velocities at each position on the movement path as a feedrate of the tool at each position on the movement path; and a deceleration recording unit which stores a type of the parameter corresponding to a case of the feedrate determination unit defining the limit velocity as the feedrate.

A method for limiting joint velocity of a plurality of joints of a surgical robotic system, the surgical robotic system comprising a robot having a base and an arm extending from the base to an attachment for an instrument, the arm comprising a plurality of joints whereby the configuration of the arm can be altered, the method comprising: obtaining joint states for a first group of k joints of the arm, where k>1; for each of the k joints: determining from the obtained joint state a permitted range of motion for that joint; deriving, using the permitted range of motion, a joint velocity limit for that joint; selecting the minimum joint velocity limit of the k joints to be a common joint velocity limit used to limit each of the k joints individually; and calculating drive signals for driving the k joints wherein the velocity of each of the k joints is limited using the common joint velocity limit.

A numerical control device for a machine tool which causes a tool to move along a movement path decided according to a machining program, the numerical control device including: a limit setting storage unit in which limit values of a plurality of parameters related to movement of the tool are set; a limit velocity calculation unit which calculates a plurality of limit velocities, which respectively correspond to the limit values at each position of the movement path; a feedrate determination unit which defines a minimum value among an ideal velocity of the tool and the plurality of limit velocities at each position on the movement path as a feedrate of the tool at each position on the movement path; and a deceleration recording unit which stores a type of the parameter corresponding to a case of the feedrate determination unit defining the limit velocity as the feedrate.

A method for limiting joint velocity of a plurality of joints of a surgical robotic system, the surgical robotic system comprising a robot having a base and an arm extending from the base to an attachment for an instrument, the arm comprising a plurality of joints whereby the configuration of the arm can be altered, the method comprising: obtaining joint states for a first group of k joints of the arm, where k>1; for each of the k joints: determining from the obtained joint state a permitted range of motion for that joint; deriving, using the permitted range of motion, a joint velocity limit for that joint; selecting the minimum joint velocity limit of the k joints to be a common joint velocity limit used to limit each of the k joints individually; and calculating drive signals for driving the k joints wherein the velocity of each of the k joints is limited using the common joint velocity limit.

A numerical controller that controls a machine based on a program, the machine including a drive unit that is driven by at least one or more ball screws, includes: instruction program analyzing unit for analyzing the program and generating movement instruction data based on an analysis result; and speed changing unit for evaluating a safe feed speed at a position that is indicated by a coordinate value of the drive unit, based on the coordinate value, and restricting a movement speed of the drive unit up to the safe feed speed, the movement speed of the drive unit being included in the movement instruction data.