A practical method for friction identification in hydraulic actuators

Performance analysis of a new hybrid cooling–drying system

Vortex tube is a mechanical device that operates as a refrigerating machine. This device separates a compressed gas stream into hot and cold streams. In this paper a series of experiments has been carried out to investigate the influence of uniform curvature of main tube on the performance of the vortex tube. Results show that the curvature in the main tube has different effects on the performance of the vortex tube depending on inlet pressure and cold mass ratio. It was found that the maximum temperature difference (ΔTc,max) belonged to straight vortex tube, type A, however the maximum refrigeration capacity ( Q ˙ c , max ) belonged to curved vortex tube, type C. Non-dimensional cold temperature difference ( Δ T c / Δ T c , max ) and non-dimensional refrigeration capacity ( Q ˙ c / Q ˙ c , max ) are found to be independent of the curvature of the vortex tube.

Experimental modeling of a curved Ranque–Hilsch vortex tube refrigerator

Smart cities essentially require the state-of-the-art technologies that can provide smart service in various aspects, and robotic systems are one of the key solutions for such requirements. Time is a critical issue when dealing with people who experience a sudden cardiac arrest that unfortunately could die due to inaccessibility of the emergency treatment. Therefore, an immediate treatment using automated external defibrillator (AED) must be administered to the victim within a few minutes after collapsing. Hence, we have designed and developed the ambulance robot, which brings along an AED in a sudden event of cardiac arrest and facilitates various modes of operation from manual to autonomous functioning to save someones lives in smart cities. The details of the design and development of such robot are presented in this paper.

Robotic Automated External Defibrillator Ambulance for Emergency Medical Service in Smart Cities

A tire position determination system (17) includes a tire pressure detector (4) attached to each tire to generate a tire pressure signal. An acceleration detector (10) generates gravitational information for each tire pressure detector (4). A receiver (12) arranged in a vehicle body receives the tire pressure signal from each tire pressure detector (4). An axle rotation amount detector (19) detects an axle rotation amount of an axle corresponding to each tire and generates pulses indicative of the detected axle rotation amount. An automatic locator (20) determines the position of each tire based on the gravitational force and the pulses. A pulse combination determination unit (24) determines whether or not a combination of the pulses from the axle rotation amount detectors (19) is appropriate. A pulse acquisition timing setting unit (25) sets an acquisition timing of the pulse signal for the automatic locator (20) based on the determination of the pulse combination determination unit (24).

Tire position determination system

In this paper, a reduced order model of dynamic and drive models augmentation of a skid steering mobile robot is presented. Moreover, a Linear Quadratic Regulator (LQR) controller augmented with a feed-forward part is designed for controlling this reduced order model. The controller is simple in terms of design and implementation in comparison with complex nonlinear control schemes that are usually designed for this system. Moreover, it provides good performance for the plant comparable with a nonlinear controller based on the inverse dynamics which depends on the availability of an accurate model describing the system. Simulation results are included.

Skid steering mobile robot modeling and control

Robots are expected to come in direct contact with human at care facilities and/or homes soon. Motivated by the application of holding and/or transferring a patient applying a robot, this paper introduces the dynamic model, static analysis and control algorithm for nonprehensile manipulation of a two-rigid-link object applying two cooperative arms. Newton-Euler equations are applied for formulating the object dynamics while a visco-elastic model is applied for modeling the interaction between the object links and the arms. Static analysis specifying the equilibrium points based on the derived dynamical model is introduced. A PD controller with a disturbance observer is designed to control the object lifting-up motion. Static analysis as well as controlled object lifting-up motion simulation results is presented which show the validity of the proposed analysis and control algorithm.

Model-based control for nonprehensile manipulation of a two-rigid-link object by two cooperative arms

As an application of mechatronics, this paper presents the advances in surface-adaptive ground penetrating radar (GPR)-based anti-personnel landmine detection project in Nagoya University. These advances can be summarized in three items: (1) GPR manipulation where a low-pressure-tire vehicle capable of moving inside a mine field, to facilitate machine-based sensing in place of manual sensing, is applied; (2) enhancement of underground landmine suspects’ images through geography adaptive scanning and measurements signal processing of a vector frequency modulated continuous wave (FMCW) GPR; (3) GPR fusion with metal detector (MD) for automatic decision making through experimental-based fuzzy learnt fusion rules. The state-of-art of these advances as well as directions for future research work is to be presented.

Advances in GPR-based landmine automatic detection

http://www.nt.ntnu.no/users/skoge/prost/proceedings/ifac11-proceedings/data/html/papers/1337.pdf

Fuzzy Nonprehensile Manipulation Control of a Two-Rigid-Link Object by Two Cooperative Arms

This paper presents kinematic analysis of free-ended two-rigid-links object manipulated by two arms as an initial step simplification towards the analysis of holding and manipulating a human body by a humanoid robot. Rolling as well as sliding at the points of contact of the two-links object constrained by the holding two-arms is explained. Position, velocity and acceleration analysis of the manipulated object, position, velocity and acceleration constraints as well as expressions for sliding displacement, sliding velocity and sliding acceleration are presented. Simulation results for links sliding acceleration, the object joint acceleration and object configurations for different input rolling accelerations are presented. The presented position, velocity and acceleration analysis proves that: 1- through manipulating two-links object by two-arms, rolling about one arm or both arms at the points of contact is associated with sliding at both points of contact. There is no rolling without sliding and there is no sliding without rolling. 2- It is possible to define the object links velocities or accelerations as well as sliding accelerations from the contact rolling velocities and accelerations estimations or measurements. 3- It is possible to define the configuration of the object from contact points and hence contact angle measurements, applying tactile sensors.

/pdf/kinematic-analysis-of-a-two-link-object-for-whole-arm-4d1h684ut5.pdf

Zakarya Zyada

Papers

Skid steering mobile robot modeling and control

Model-based control for nonprehensile manipulation of a two-rigid-link object by two cooperative arms

Advances in GPR-based landmine automatic detection

Fuzzy Nonprehensile Manipulation Control of a Two-Rigid-Link Object by Two Cooperative Arms

Kinematic analysis of a two-link object for whole arm manipulation