Advanced Robotics

Luna-Aguilar, C. A.; Morales-Díaz, A. B.; Castelán, M.; Nadeu, C.

doi: 10.1080/01691864.2019.1573703pmid: N/A

This article introduces the incorporation of acoustic sensors for the localization of a mobile robot. The robot is considered as a sound source and its position is located applying a Time Delay of Arrival (TDOA) method. Since the accuracy of this method varies with the microphone array, a navigation acoustic map that indicates the location errors is built. This map also provides the robot with navigation trajectories point-to-point and the control is capable to drive the robot through these trajectories to a desired configuration. The proposed localization method is thoroughly tested using both a 900 Hz square signal and the natural sound of the robot, which is driven near the desired point with an average error of 0.067 m.

Zhang, Shuaishuai; Fan, Mingqu; Li, YiBin; Rong, Xuewen; Liu, Ming

doi: 10.1080/01691864.2019.1566089pmid: N/A

Generating a robust gait is one of the most important factors to improve the adaptability of quadruped robots on rough terrains. This paper presents a new continuous free gait generation method for quadruped robots capable of walking on the rough terrain characterized by the uneven ground and forbidden areas. When walking with the proposed gait, the robot can effectively maintain its stability by using the Center of Gravity (COG) trajectory planning method. After analyzing the point cloud of rough terrain, the forbidden areas of the terrain can be obtained. Based on this analysis, an optimal foothold search strategy is presented to help quadruped robot to determine the optimum foothold for the swing foot automatically. In addition, the foot sequence determining method is proposed to improve the performance of robot. With the free gait proposed in this paper, quadruped robot can walk through the rough terrains automatically and successfully. The correctness and effectiveness of the proposed method is verified via simulations.

Asker, Ahmed; Assal, Samy F. M.

doi: 10.1080/01691864.2019.1573152pmid: N/A

Recently, the potential of assistive robots to enhance independence and quality of life for elderly and disabled has been given much attention. Designing a multi-function sit-to-stand assistive device is a challenging task due to the high payload and large workspace requirements. In this paper, a parallel manipulator-based assistive device is proposed to assist in various lower limb activities. The device is constructed based on a non-conventional structure of a 3- parallel manipulator, that provides partial kinematic decoupling between position and orientation and suitable singularity-free workspace as well as high rigidity and payload capability. Furthermore, dimensional synthesis based on maximizing the workspace index as well as the global force transmission and stiffness indices, is performed to optimize the device dimensions. A prototype of the device is manufactured based on the optimized dimensions. The ability to assist subjects with different stature heights to stand up in a natural manner is asserted by experiments conducted using the prototype.