An investigation of the potential for improvement of tractor draught controls

Abstract Previous work has shown the inadequacy of tractor draught controls particularly when working at higher speed. An experimental implement control unit on which several parameters could be varied was built and experiments were carried out in a number of different field conditions to investigate the effect of varying the parameters with an artificial sinusoidal draught variation input. A computer model was devised to predict performance and the results are compared with experimental measurements. Agreement is satisfactory and the results are used to suggest how performance may be improved without inducing instability.