A robot controller is adapted to execute a program an indication of a setpoint speed of a robot arm, an indication of a contemporaneous setpoint fluid flow per unit time of a spray gun supported by the robot arm, and an indication of a contemporaneous further setpoint quantity of the spray gun. The robot controller is configured to obtain an estimate of actual speed of the robot arm; determine whether the estimate deviates from the setpoint speed; and, in case of a deviation, adjust the setpoint fluid flow per unit time in accordance with a first compensation function. In an embodiment, the robot controller is further configured to concurrently adjust, in case of a deviation, the further setpoint quantity in accordance with a second compensation function, which is different from the first compensation function.

A display control device according to an embodiment controls display of a state of a machine tool that includes (i) an attachment portion to which a tool is attachable, (ii) a numerical control unit for controlling (a) movement of the attachment portion and (b) a rotating speed of the tool in accordance with a machining program and (iii) a vibration detection unit for detecting vibration of the tool. This display control device includes a display control unit for controlling display of time-series data indicating (i) a change in a vibration level detected by the vibration detection unit and (ii) a change in the rotating speed of the tool. Upon receiving an instruction to change the rotating speed, the display control unit controls the display so that a marker indicating the change instruction is superimposed on the time-series data.