The present disclosure relates to a method for controlling an autonomous robotic tool using a modular autonomy control unit. The control unit includes an interface with the autonomous robotic tool and comprises a processor, configured to control the autonomous robotic tool during operation. The modular autonomy control unit transfers a set of test instructions to the autonomous robotic tool, triggering the latter to carry out a set of test actions in response to the test instructions—The modular autonomy control unit detects sensor input in response to the test actions, and computes a corresponding error vector, based on which calibration data is updated. Then, the modular autonomy control unit controls the robotic tool based on the calibration data. This allows a general control unit to be used in connections with several types of robotic work tools.