An autonomous skid-steer machine for performing agricultural operations, the machine comprising - a chassis; a plurality of ground engaging elements supporting the chassis on a ground surface; one or more computing devices for controlling movement of the machine, the one or more computing devices configured to - generate a control signal for controlling operation of at least some of the plurality of ground engaging elements to cause the machine to move in a forward direction and to turn the machine, the control signal being generated according to a control algorithm incorporating tuning parameters, characterised in that the one or more computing devices are further configured to - automatically determine the tuning parameters in real time during operation of the machine such that the control algorithm is always optimized for a current speed of the machine, wherein the tuning parameters are found using the machine's current speed, a natural frequency value ( ω 0) and a damping value (ζ), wherein the natural frequency value ( ω 0) determines reactiveness of the machine as it responds to navigational errors, wherein the damping value (ζ) determines overshoot of the machine as it responds to navigational errors. a chassis; a plurality of ground engaging elements supporting the chassis on a ground surface; one or more computing devices for controlling movement of the machine, the one or more computing devices configured to - generate a control signal for controlling operation of at least some of the plurality of ground engaging elements to cause the machine to move in a forward direction and to turn the machine, the control signal being generated according to a control algorithm incorporating tuning parameters, characterised in that the one or more computing devices are further configured to - automatically determine the tuning parameters in real time during operation of the machine such that the control algorithm is always optimized for a current speed of the machine, wherein the tuning parameters are found using the machine's current speed, a natural frequency value ( ω 0) and a damping value (ζ), wherein the natural frequency value ( ω 0) determines reactiveness of the machine as it responds to navigational errors, wherein the damping value (ζ) determines overshoot of the machine as it responds to navigational errors. generate a control signal for controlling operation of at least some of the plurality of ground engaging elements to cause the machine to move in a forward direction and to turn the machine, the control signal being generated according to a control algorithm incorporating tuning parameters, characterised in that the one or more computing devices are further configured to - automatically determine the tuning parameters in real time during operation of the machine such that the control algorithm is always optimized for a current speed of the machine, wherein the tuning parameters are found using the machine's current speed, a natural frequency value ( ω 0) and a damping value (ζ), wherein the natural frequency value ( ω 0) determines reactiveness of the machine as it responds to navigational errors, wherein the damping value (ζ) determines overshoot of the machine as it responds to navigational errors.