1,720,999 research outputs found
Energy-saving optimization method for point-to-point trajectories planned via standard primitives in 1-DoF mechatronic systems
Full text linkIn this work, an analytical methodology to minimize the energy expenditure of mechatronic systems performing point-to-point (PTP) trajectories based on well-known motion primitives is developed and validated. Both PTP trajectory profiles commonly used in industrial motor drives and more complex ones are investigated. Focusing on generic 1-DoF mechatronic systems moving a constant inertia load (e.g., elevators, cranes, CNC machines, Cartesian axis) and possibly equipped or retrofitted with regenerative devices, the consumed energy formulation is firstly derived. Then, the analytical optimization considering all the selected PTP trajectory profiles is computed and a generic closed-form solution is determined. Finally, numerical and experimental evaluations are done showing the effectiveness of the theoretical results and proposed methodology. In addition, all the different trajectories are compared with respect to energy consumption
Minimization of the energy consumption in industrial robots through regenerative drives and optimally designed compliant elements
Full text linkThis 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
Optimal Path Planning Method for A Bush Trimming Robot with A Non-omnidirectional End-effector
No full textNowadays, the operation of trimming artistic bushes is generally performed by skilled human operators without any technological support. This entails that such an operation is characterized by a variability in terms of quality and that it can be performed only with adequate weather conditions. This work addresses the problem of developing a robotized pruning workstation to accurately trim an artistic bush by kinematically modelling the cutting operation, deriving and proving the kinematic constraints which ensure a good quality of the cutting operation, and adapting and improving a state of the art coverage path planning algorithm. Such approach has been validated both numerically and experimentally, showing a consistent improvement with respect to the state of the art algorithms
Energy saving in mechatronic systems through optimal point-to-point trajectory generation via standard primitives
No full textOn the trajectory planning for energy efficiency in industrial robotic systems
Full text linkIn this paper, we present an approach for the minimum-energy trajectory planning in industrial robotic systems. The method is based on the dynamic and electro-mechanical modeling of one-degree-of-freedom systems and the derivation of the energy formulation for standard point-to-point trajectories, as, for instance, trapezoidal and cycloidal speed profiles. The proposed approach is experimentally validated on two robotic systems, namely a linear axis of a Cartesian manipulator built in the 1990’s, and a test bench composed of two servomotors directly connected or coupled by means of a planetary gear. During the tests, the electrical power expended by the systems is measured and integrated over time to compute the energy consumption for each trajectory. Despite the limitations of the energy measurement systems, the results reveal a trend in agreement with the theoretical calculations, showing the possibility of applying the method for enhancing the performance of industrial robotic systems in terms of energy consumption in point-to-point motions
An energy-efficient approach for 3D printing with a Linear Delta Robot equipped with optimal springs
No full textIn this paper a novel approach for sustainable 3D printing with a Linear Delta Robot equipped with elastic elements is presented and experimentally validated. Energy saving is achieved thanks to the introduction and optimization of linear springs that are mounted on the robot with different configurations: in parallel to the prismatic joints, or directly connecting the end-effector to the fixed frame. The elastic elements allow for a conversion between potential and kinetic energy during a cyclic motion, as for instance the printing of a material layer in additive manufacturing, resulting in actuators energy saving. To reduce the energy consumption, the spring parameters are optimized for the different scenarios by considering the kinematic, dynamic and electro-mechanical models of the parallel robot performing a 3D printing trajectory. The proposed approach is experimentally validated, showing an energy reduction up to almost 50% with respect to the nominal case without springs. The method is general and can be applied for energy efficiency and sustainability in several fields of robotics and computer-integrated manufacturing
Development of a Climbing-Robot for Spruce Pruning: Preliminary Design and First Results
No full textEvaluation of a Lidar-based 3D-stereoscopic vision system for crop-monitoring applications
No full textWhen dealing with unmanned agricultural vehicles (remotely-controlled vehicles, robots), vision systems
are a key-factor for implementing field-solutions having direct interactions with crops.
Among all the possible information given by a vision system, the punctual estimation of the canopy
volume is surely an interesting parameter: it is related to the crop vegetative status and, hence, it is fundamental
for performing and setting-up properly some important field-operations (e.g., pruning/thinning,
spraying). A system able to recognize the canopy volume can provide either the input-signals for
implementing a robotic real-time site-specific farming system or relevant information for a proper crop
management. However, there are many practical difficulties in the field implementation of such a system:
complex canopy shapes, different colours, textures and illumination conditions with projected shadows.
Terrestrial/aerial vision systems working on visible-light wavelengths and/or 2D-images of crops,
although capable of excellent performances, have a computationally-heavy post-processing; therefore,
they are unsuitable for implementing low-cost real-time servo-actuated cropping systems (e.g., robotised
sprayers). Instead, a vision system composed by two LiDAR sensors aligned vertically, scanning the same
targets, could give a sort of stereoscopic vision, here named ‘‘lateral-linear-stereoscopic vision”.
The aim of this study is assessing the opportunity to use such a system on an automatic or autonomous/
robotised implement by performing some preliminary tests in a controlled environment. The
resulting system is independent of the lighting conditions (it works also in the dark), is highly reliable
(no projected shadows) and data processing is very fast. Although further studies are required to overcome
the issues that could arise in a future field implementation, this system has all the premises to
be successfully embedded in an automatized monitoring system
Cutting systems evaluation for a tree-pruning robot
No full textForests play a crucial role in limiting climate changes (i.e., through CO2 storage, and by using wood in construction, thus preventing the emission of CO2 for the production of alternative building materials like concrete and plastic) and in mitigating its adverse effects (i.e., soil erosion and flooding). In this context, the sustainable management of forests has gained significant attention in recent years. In spruce forests, to maintain the ecological health and preventing wildfire, a proper spruce-tree pruning could be a possible solution. Moreover, this operation allows to improve the quality of the timber, by limiting the growth/formation of dead-knots. However, it typically requires specialized labour and longer execution times. In this study, an additional step regarding the design and implementation of an automatic spruce pruning robotic system is presented. In particular, this paper focuses on the experimental evaluation and selection of the most suitable cutting system to equip this robot. The results show how the pruning shears are the tool that can guarantee a more precise cut and a faster execution without destabilizing the climbing platform during the cutting operation. In any case, the indicated pruning shears require a branch detection system and a fairly precise positioning system to be effective
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