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Inchworm robots are typical insect bionic robots that are able to move in narrow space such as pipelines, which expand the range of robot application. In this paper, the motion control method of the bionic sucker inchworm robot (BSIR) based on MPC is proposed, which enables the inchworm robot to achieve “ $\Omega $ ” motion gait and steering gait on vertical and horizontal planes of different materials. Firstly, the negative pressure suction cup imitating octopus tentacles (NPSC-IOT) is designed and the sucker control model is proposed. Under negative pressure control, the adsorption pressure of the sucker is adjusted to satisfy the needs of the trunk structure movement. Secondly, the bionic sucker controller based on MPC is designed, and the closed-loop control is realized by using the data feedback from the air pressure sensor. Thirdly, BSIR with installed NPSC-IOT as the robot’s tentacles is developed. Finally, the experiment verifies the feasibility of the bionic sucker controller based on MPC to control BSIR to achieve ‘ $\Omega $ ’ motion gait and steering gait on vertical and horizontal planes of different materials. The experimental results show that BSIR is able to achieve “ $\Omega $ ” gait and turning gait on vertical and horizontal surfaces of glass, tiles, white gray walls, and metal. more...

Hybrid mobile robots with two motion modes of a wheeled vehicle and truss structure with the ability to climb poles have significant flexibility. The motion planning of this kind of robot on a pole has been widely studied, but few studies have focused on the transition of the robot from the ground to the pole. In this study, a locomotion strategy of wheeled-legged pole-climbing robots (the WL_PCR) is proposed to solve the problem of ground-to-pole transition. By analyzing the force of static and dynamic process in the ground-to-pole transition, the condition of torque provided by the gripper and moving joint is proposed. The mathematical expression of Centre of Mass (CoM) of the wheeled-legged pole-climbing robots is utilized, and the conditions for the robot to smoothly transition from the ground to the vertical pole are proposed. Finally, the feasibility of this method is proved by the simulation and experimentation of a locomotion strategy on wheeled-legged pole-climbing robots. more...

Various extraction methods have been used to determine selenium (Se) concentrations in soils and plants in the second seleniferous regions of China. Our results show tea Se contents in the study area range from 1.009 to 2.6 mg/kg, which reveal that the tea areas in Ziyang County are in seleniferous regions. The four extraction methods evaluated in this study provide different information concerning soil and plant Se levels. The quality control/quality assurance program for this project indicated there is excellent agreement between total soil Se and extractable Se. For example, phosphate extractable Se results from the field investigation and greenhouse study were found to be highly correlated ( R 2 > 0.91) by linear regression analyses. Results from rye seedling experiments further show phosphate extractable Se has significant correlations with plant Se uptake and that a 0.1 M solution of KH2PO4 can be used as the extractant of soil available Se. In the acid soil, the Brassica campestris yield could be significantly reduced when the content of Se6+–Se ≥ 0.5 mg/kg, and the influence on the yield was not as obvious when the content of Se6+–Se reached up to 2.0 mg/kg. The uptake by Brassica campestris of Se6+–Se is higher than that of Se4+–Se. The main factors influencing the biological availability of soil Se, in order of their importance are CaCO3, the presence of silt grains, organic matter and the presence of clay grains. pH could affect KH2PO4 extractable Se through CaCO3. [ABSTRACT FROM AUTHOR] more...