Grasslands are the most extensive terrestrial landscapes and ecosystems in China and face growing degradation. A policy to protect the grasslands established in 2001 (the Grassland Ban Policy [GBP]), involves four management practices including grazing bans, keeping grasslands fallow, grazing rotations and rearing livestock in sheds. A questionnaire was developed and used to establish attitudes towards and beliefs about the GBP in different sectors (farming households, local officials and extension workers), assess problems with GBP implementation and identify possible solutions. Acceptance of the GBP by farmers varied from 64% in the north to 95% in the northwest region. The responses of both local officials and extension workers indicated that GBP implementation was greater in the central region than in the northwest region. Most farmers changed their livestock production system from grazing to stall feeding after implementation of the GBP, while both farmers and extension workers reported that high input costs were the most serious problem in stall feeding. Incentives need to be provided for sustainable implementation of the GBP by different stakeholders. Improved collaboration among farmers, local officials and extension workers is needed for technology transfer and policy implementation. Furthermore, the role of non-governmental organizations needs to be strengthened in implementation of the GBP.

No abstract

This article presents a design of novel wheelchair with a leg exoskeleton for locomotion that can be powered by user legs through a cycling action. In addition, the control system is designed with leg-motion assistance for lower limb muscles to perform exercise during wheelchair motion, targeting elderly persons and users with partial hemiplegia. The simulation results characterize the dynamic operation in three possible modes, fully active, fully passive, and user passive-active action.

The muscles of the lower limbs directly influence leg motion, therefore, lower limb muscle exercise is important for persons living with lower limb disabilities. This paper presents a medical assistive robot with leg exoskeletons for locomotion and leg muscle exercises. It also presents a novel pedal-cycling actuation method with a crank-rocker mechanism. The mechanism is driven by a single motor with a mechanical structure that ensures user safety. A control system is designed based on a master-slave control with sensor fusion method. Here, the intended motion of the user is detected by pedal-based force sensors and is then used in combination with joystick movements as control signals for leg-exoskeleton and wheelchair motions. Experimental data is presented and then analyzed to determine robotic motion characteristics as well as the assistance efficiency with attached electromyogram (EMG) sensors. A typical muscle EMG signal analysis shows that the exercise efficiency for EMG activated amplitudes of the gluteus medius muscles approximates a walking at speed of 3 m/s when cycling at different speeds (i.e., from 16 to 80 r/min) in a wheelchair. As such, the present wheelchair robot is a good candidate for enabling effective gluteus medius muscle exercises for persons living with gluteus medius muscle disabilities.

No abstract

No abstract

Biped robots with dynamic motion control have shown strong robustness in complex environments. However, many motion planning methods rely on models, which have difficulty dynamically modifying the walking cycle, height, and other gait parameters to cope with environmental changes. In this study, a heuristic model-free gait template planning method with dynamic motion control is proposed. The gait trajectory can be generated by inputting the desired speed, walking cycle, and support height without a model. Then, the stable walking of the biped robot can be realized by foothold adjustment and whole-body dynamics model control. The gait template can be changed in real time to achieve gait flexibility of the biped robot. Finally, the effectiveness of the method is verified by simulations and experiments of the biped robot BHR-B2. The research presented here helps improve the gait transition ability of biped robots in dynamic locomotion.

No abstract