Current Issue : October - December Volume : 2015 Issue Number : 4 Articles : 5 Articles
The paper presents a framework that can be used to design and optimize a balancing mechanism for an industrial robot. The\nframework has the capability to optimize three different concepts: a mechanical, a pneumatic, and a hydropneumatic. Several\ndisciplines are included in the framework, such as dynamic and static analyses of the robot performance.Optimization is performed\nfor each concept and the obtained optimal designs are all better than the reference design. This means that the framework can be\nused as a tool both to optimize the balancing mechanism and also to support concept selection....
The Theo Jansen mechanism is gaining widespread popularity among the legged robotics community due to its scalable design,\nenergy efficiency, low payload-to-machine-load ratio, bioinspired locomotion, and deterministic foot trajectory. In this paper, we\nperform for the first time the dynamic modeling and analysis on a four-legged robot driven by a single actuator and composed of\nTheo Jansen mechanisms. The projection method is applied to derive the equations of motion of this complex mechanical system\nand a position control strategy based on energy is proposed. Numerical simulations validate the efficacy of the designed controller,\nthus setting a theoretical basis for further investigations on Theo Jansen based quadruped robots....
This paper presents a versatile method to install a small machining robot onto a planar or slightly curved object. Normally, gripping\ntools provide a rigid connection between a robot and a target. However, if there is no graspable area on the target, the gripper\ncannot perform well. To overcome this problem, we proposed a deformable device that works as a universal suction pad and that\ncan hold an ungraspable target by utilizing the jamming transition phenomenon. We determined the effect of the type of grains\non the jamming transition phenomenon in terms of stability under jammed conditions. By comparing the four types of grains,\nwe found that the tetrahedral-shaped grains performed the best. Subsequently, we evaluated the performance of the device. The\nsuction force was 166-N when the proposed device was affixed to a curved target. Next, we evaluated the stiffness of the device. The\naverage deformations of the device were 0.10 mm, 0.35 mm, and 0.04 mm, respectively, when 50-N downward vertical, horizontal,\nand upward vertical directional loads were applied to the device, which was affixed to the curved target. The results suggest that the\nproposed device performed well in affixing a robot onto a target....
For liquid transfer system in three-dimensional space, the use of multijoint robot arm provides much flexibility. To realize quick\npoint-to-point motion with minimal sloshing in such system, we propose an integrated framework of trajectory planning and\nsloshing suppression. The robot motion is decomposed into translational motion of the robot wrist and rotational motion of the\nrobot hand to ensure the upright orientation of the liquid container.The trajectory planning for the translational motion is based on\ncubic spline optimization with free via points that produces smooth trajectory in joint space while it still allows obstacle avoidance\nin task space. Input shaping technique is applied in the task space to suppress the motion induced sloshing, which is modeled as\nspherical pendulum with moving support. It has been found through simulations and experiments that the proposed approach is\neffective in generating quick motion with low amount of sloshing....
In order to implement automatic spraying on Hyphantria cunea larva nets, a spraying robot system with monocular hand-eye\ncoordination and smart targeting abilities was designed according to the target net features. The system realized spatial two dimensional\nmotions driven by step motors on linear guide rails. Images were processed in real-time to extract the net curtain\ntargets defined using the border area, and the optimal spraying position was then determined. An identification algorithm based\non the global net image to distinguish targets before and after spray was proposed. A simulation environment was designed to verify\nthe correctness of this method. Results showed that the highest rate of over spray is 288.5%, and the spray miss rate is 0....
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