Choice of motor and transmission in mechatronic applications: Non-rectangular dynamic range of the drive system

•General dynamic operating range of the drive system•A known graphical method was applied to the case of a non-rectangular dynamic range.•New representation of the drive system•A sufficient condition in order to assure the motor admissibility•Feasibility and uncertainty ranges of the transmission ratio

This paper deals with the choice of the motor–transmission couple suitable to move a joint with reference to the dynamic operating range of the drive system, introducing the case in which its limit curve depends on the motor speed in a general way. The paper explains the problems arising in this case and how the design approach can be modified with respect to a rectangular operating range. A graphical method is proposed, which permits the designer to exclude some drive systems and, for each of the others, to find a range of transmission ratios that can certainly be coupled with the motor and/or a range of transmission ratios for which the analysis must be deepened.