The Effect of Dimensional Parameters on the Performance of DDMRs

Differential drive mobile robots (DDMRs) are often used in automation research because they are simple mechanically, and low cost as they only require two motors to drive and steer. Work to date has focused on control, with little done to optimise these vehicles in terms of dimensional parameters such as centre of mass position, track width, wheel base and caster dimensions. This paper presents a dynamic model of a DDMR and the dimensional sensitivity of peak drive/braking force, energy consumption, and chassis forces is assessed. The model is applied to a range of trajectories typical in an agricultural setting. Results show that these are all sensitive to vehicle dimensions to different degrees. Energy consumption showed the least sensitivity, while drive forces were found to be significantly influenced, for example, increasing the caster trail from 0.13 to 0.33 m decreased peak drive force by 56%. Optimising dimensional parameters in DDMRs can contribute to more economically viable automated solutions through increased efficency and reduced expense.