A Novel Design Concept for Energy-Efficient Manipulators Based on Straight-Line Linkages

Abstract Minimizing the energy consumption of robot manipulators is essential to address both environmental and economic challenges. This study introduces a novel design concept for manipulators that reduces energy use in both static and dynamic operating modes. The key idea is to employ straight-line guiding linkages as the manipulator's actuating system. This approach enables the elimination of static loads on the actuators without fixing the manipulator's overall center of mass. Instead, the center of mass follows a rectilinear horizontal trajectory, maintaining constant potential energy. As a result, the system requires fewer counterweights and experiences a smaller increase in total moving mass. Two manipulator architectures are presented, inspired by the Scott–Russell and four-bar mechanisms. For dynamic operation, an optimal design method is developed to minimize input torques. By carefully tuning the counterweight parameters, the manipulator achieves energy-efficient performance across a family of “Pick-and-Place” trajectories, each executed according to a “Bang-Bang” motion control law. The results clearly illustrate the transition between static and dynamic modes and demonstrate a substantial reduction in input torque in both cases. The proposed method is generalizable to other manipulator types and provides an effective framework for optimizing robotic energy performance.