NOVELTY - The robot has an arm influencing a platform in movement. The arm comprises a link with an outer joint connected to the platform and an inner joint. A linear actuator is connected to a carriage and to the inner joint of the link of the arm. The linear actuator linearly moves the link of the arm relative to the connected carriage, where the link with adjustable length is designed together with a position of the actuator to minimize deviations from 90 degrees between the link of the arm and links of other two arms.    USE - Industrial robot for moving a very long object e.g. tool/work object such as airplane wing, wind power blade, wing component and steel beam, in a space for robot applications e.g. drilling, cutting, deburring, milling and grinding applications, in hard materials such as steel and iron.    ADVANTAGE - The actuator is mounted on the carriage to linearly move the outer joint of the link in relation to other carriages instead of integrating the actuator with the link, actuates the platform by moving the outer joint of the link instead of changing the length of the link, so that the actuator does not add any inertia to a link structure, thus allowing the robot to operate in the applications requiring high speed and acceleration. The link of the arm with the actuator for controlling the length of the link controls inclination of the link, thus maximizing stiffness of the robot with respect to tool forces.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a method for controlling an industrial robot    (2) a computer program product comprising a set of instructions for controlling an industrial robot.    DESCRIPTION OF DRAWING(S) - The drawing shows a flow chart illustrating a method for controlling robot configuration to increase stiffness of a robot.    Step for starting movement of manipulator (90)    Step for performing kinematic calculations of link (91)    Step for checking whether robot is designed for maximum stiffness mode (92)    Step for calculating angles between links of robot (93)    Step for performing actuator control (97)