A Barycenter Control Method for the Bioinspired Forest Chassis Robot on Slope

To improve the stability of forestry chassis on the slope, a chassis-installed barycenter adjustable mechanism (BAM) is designed, and the control method of the counterweight is proposed to make the chassis barycenter move suitably to achieve the design purpose. The kinematic analysis of BAM is carried out, and the relationship between the translation, rotation, and vertical displacement of counterweight and the chassis barycenter is calculated. Furthermore, the variation curves obtained in Matlab show the barycenter can translate 100 mm, rotate from 0 to 360 degrees, and lower about 180 mm in the vertical direction. Adams is adopted to complete the kinematics simulation of the chassis, indicating that the control method can effectively adjust the barycenter position. Finally, experiments are carried out under slope conditions to analyze chassis stability by testing plantar pressure. The results show that forest chassis using the barycenter control method helps keep stable on the slope of 15 degrees, much better than standard normal chassis.

Design and experimental study of a passive power-source-free stiffness-self-adjustable mechanism

Passive variable stiffness joints have unique advantages over active variable stiffness joints and are currently eliciting increased attention. Existing passive variable stiffness joints rely mainly on sensors and special control algorithms, resulting in a bandwidth-limited response speed of the joint. We propose a new passive power-source-free stiffness-self-adjustable mechanism that can be used as the elbow joint of a robot arm. The new mechanism does not require special stiffness regulating motors or sensors and can realize large-range self-adaptive adjustment of stiffness in a purely mechanical manner. The variable stiffness mechanism can automatically adjust joint stiffness in accordance with the magnitude of the payload, and this adjustment is a successful imitation of the stiffness adjustment characteristics of the human elbow. The response speed is high because sensors and control algorithms are not needed. The variable stiffness principle is explained, and the design of the variable stiffness mechanism is analyzed. A prototype is fabricated, and the associated hardware is set up to validate the analytical stiffness model and design experimentally.

MRI after successful eyeWatchTM implantation

The eyeWatchTM is a new glaucoma drainage device that includes an adjustable mechanism that can vary the resistance to aqueous humor outflow during the postoperative period to reduce the burden of postoperative intraocular pressure (IOP) management. The mechanism contains a magnetic rotor that can be adjusted using an external magnetic control unit. Adjustments of the position of the rotor are performed mostly in the initial postoperative follow-up period in order to reach the target IOP. However, for some patients, it might be necessary to perform MRI for the sake of medical investigations. As the MRI is creating a strong magnetic field, this magnetic field is likely to interact with the adjustable rotor of the eyeWatchTM, resulting in modification of the IOP. We report the case of an 82-old female patient successfully operated with the implantation of an eyeWatchTM. The patient underwent a cerebral MRI for persistent headache. Shortly after the MRI procedure, the patient was checked at the eye clinic to assess the position of the rotor and to measure the IOP. The eyeWatchTM was readjusted to the former position set before undergoing the MRI. No complications were reported in the follow-up after MRI. This case demonstrates that MRI examinations can be safely performed after glaucoma surgery using an eyeWatchTM without compromising on the quality of the imaging or the stability of the IOP. This is a complication-free procedure that only requires checking the new position of the rotor and re-adjusting the implant, if necessary, to achieve the target IOP.

Computational analysis of the steady state performance of an adjustable/controllable multi-pad bearing profile under LBP orientations

A theoretical model of a four-pad bearing profile with unique adjustable or controllable features is simulated in the present study by considering load directed between the pads. Radial and tilt adjustable mechanism of the four bearing pads can effectively control and modify the rotor operating behaviour. Inward and outward motions of the bearing pads result in the generation of narrow and broader convergent regions, which directly influences the fluid film pressures. In the theoretical analysis, load-between-pad (LBP) orientations and pad adjustment configurations are taken account of by employing a modified film thickness equation. The effect of load position in influencing the steady state behaviour of the four-pad adjustable bearing under varied pad displaced conditions is analysed in this study. The outcome of the analysis highlighted the effectiveness of four-pad adjustable bearing in improving the steady state performance by operating under negative adjustment conditions and with load acting on the bearing pads.

Design and Development of Pipe Inspection Robot Meant for Resizable Pipe Lines

Daily tasks mixed with the various applications in the robotic field. Since past, pipes have been used as the safe fluid transmitter. But gradually, these pipes affected by fatigue, cracking, leakage, sediment and breaking down. Also, sometimes humid environment and chemical products existing in the soil, causes rust and fatigue the pipes. All these problems lead to redundancy and impose high expenses for installation and maintenance. One of the recent inspection ways, is using the robot controller which leads to help and reduces the inspection time and preventive repairs activity. Besides, sometimes there are some unpleasant situation such as unfit pipes. It is obvious that in these conditions, doing inspection in toxic arena, narrow and meandering ways is impossible by human. So, designing a pipe inspection robot can be helpful in such circumstances. In this design, first, the former study, the way of operation, movement, mechanisms and advantages of each robot have studied. Then, by considering important parameters in designing, and sketching, making robot with the help of CATIA took place. This structure enjoys a regular mechanism design. It also has a proportional pipe diameter with the possibility of crossing through the slope routes. On the other hand, recording and processing of visual report, needs a camera and GUI toolbox written in Matlab. So image processing can help to exact investigation. One of the main difference of this research work over the various test on the platform, is hiring the mentioned toolbox which helps the operator to have the double investigation inside of the pipes. Moreover, the adjustable mechanism to pipe diameter, polyhedral movement and ascension power, relatively high efficiency in order to use frictional power and reducing repair and pause time are the advantages of this design. Also, observing the inner side of the pipe on the monitor, leads to reducing images. Moreover, its investigation by the introduced toolbox, causes more effective observation, more quickly diagnosis and analysis.