A vehicle accessory arrangement (2) structured to be mounted on a vehicle (4), the accessory arrangement (2) comprises a working equipment (6), an accessory control unit (8) configured to determine accessory control signals (10) and to control said working equipment (6) by said signals, and an accessory communication bus (12) comprising a bus interface (14) configured to connect said accessory communication bus (12) to a vehicle communication bus (16) provided at said vehicle. The accessory arrangement (2) comprises a wireless signal receiver (18) configured to receive current position data, e.g. GPS data, and working assignment data including route data for a working assignment for said vehicle (4) provided with said working equipment (6).
The accessory control unit (8) is configured to receive a vehicle data set among a plurality of different vehicle data sets, each of said plurality of vehicle data sets comprises control characteristics of a vehicle on which the accessory arrangement may be mounted. The accessory control unit (8) is configured to determine, based upon said control characteristics, navigation and drive control commands adapted to control said vehicle (4) provided with said vehicle accessory arrangement (2) to work in an autonomous mode and to travel along a route of a working assignment, and working control commands adapted to control said vehicle (2) such that working procedures performed by said working equipment (6) are supported. And that the accessory control unit (8) is configured to control said vehicle (4) provided with said vehicle accessory arrangement (2), by said determined navigation and drive commands and working control commands, to fulfil said working assignment.