Minimization of the Energy Consumption in Industrial Robots through Regenerative Drives and Optimally Designed Compliant Elements

Abstract

This paper describes a method for reducing the energy consumption of industrial robots and electrically actuated mechanisms performing cyclic tasks. The energy required by the system is reduced by outfitting it with additional devices able to store and recuperate energy, namely, compliant elements coupled in parallel with axles and regenerative motor drives. Starting from the electromechanical model of the modified system moving following a predefined periodic path, the relationship between the electrical energy and the stiffness and preload of the compliant elements is analyzed. The conditions for the compliant elements to be optimal are analytically derived. It is demonstrated that under these conditions the compliant elements are always beneficial for reducing the energy consumption. The effectiveness of the design method is verified by applying it to two test cases: a five-bar mechanism and a SCARA robot. The numerical validations show that the system energy consumption can be reduced up to the 77.8% while performing a high-speed, standard, not-optimized trajectory.

Supercapacitor Constant-Current and Constant-Power Charging and Discharging Comparison under Equal Boundary Conditions for DC Microgrid Application

“…The stored energy EC is known in advance, as it is calculated using the same Equation (5). Therefore, the lost energy ER is calculated as the difference between ESC and EC, while the full efficiency of the charging process is calculated using the same Equation (8). The efficiency of real-time power storage is calculated using the same Equation (12).…”

“…SCs are therefore useful for applications such as electric vehicle drives, which regenerate electrical power during braking mode, and this regenerated power can be stored for re-use in the next acceleration mode, thus reducing the full consumption of electricity from a power supply substation in the case of public electric transport connected to an overhead grid [6]. Power recovery is topical also in equipment used in the production industry, including industrial robots [2,7,8]. In the above mentioned situations, the use of SC ESS is an optimal choice to reduce energy consumption.…”

Modeling, Design and Optimization of Flexible Mechanical Systems

“…Palomba et al [53] Minimization of the energy consumption in industrial robots through regenerative drives and optimally designed compliant elements presents a method to retrofit mechanical systems to recover and store energy based on numerical simulation and an optimization routine.…”

The Role of Environmental Management Systems and Energy Management Systems in the Adoption of Energy Recuperation Technologies in Central European Manufacturing Companies

“…Here, ERTs are considered a group of technologies used in manufacturing companies to recover kinetic and process energy (e.g., waste heat recovery, energy storage). Examples of these technologies include the organic Rankine cycle (ORC), able to generate electricity from low-temperature heat sources [4]; flue gas waste heat recovery; waste heat recovery from cooling water; top-pressure recovery turbines that recover energy from high-pressure steam and uses it to power the turbine [5]; equipping robots with additional components capable of storing and recovering energy, specifically, compliant elements connected in parallel with axles and regenerative motor drives [6]; and the use of direct current (DC) sub-grids in industrial robot power flow, which is ideal for recovering energy from the actuators with regenerative approaches [7].…”