Adjustable Legs Research Articles

Design and analysis of an adjustable Stephenson-III closed-chain leg mechanism and its application in multi-legged robot

To improve the insufficient adaptability of single degree-of-freedom (DOF) closed-chain legs to unknown surroundings, this paper studies a novel adjustable closed-chain leg mechanism. Based on the traditional six-bar Stephenson-III leg mechanism, we add one degree-of-freedom to realize the adjustment of frame rod position, by which different shapes of foot trajectory curves are obtained. The height of the foot trajectory can be adjusted longitudinally to enhance the obstacle-surmounting ability, and the length of the walking stride can be changed in the transverse direction to achieve the landing point placement of the swing leg. The structure optimization, gait analysis and obstacle-surmounting simulation in different scenarios are carried out. The test results of walking ability and obstacle surmounting performance in specific surrounding show that the designed closed-chain leg mechanism can increase the maximum obstacle-crossing height and walking stability, which proves the promising characteristics of the proposed leg mechanism in the application of multi-legged robots.

Design and analysis of a wheel-leg compound variable curvature ship hull cleaning robot

Underwater robotic cleaning devices are promising in ship hull maintenance for biofouling removal, but there are still some challenges for commercial application. Due to the complex surface of the ship hull, larger adsorptive force is needed for climbing robots to solve the problem of poor fitting between rigid structure and ship hull, which calls for more driving power. To mitigate the gap, this paper proposed a flexible wheel-leg composite moving mechanism for ship hull cleaning robots. The designed adjustable wheel leg, which is composed of three leg frames on the rotating shaft, eliminates the magnetic wheel's position constraints and expands the movement space. The relation equations of flip angle, pitching angle, turning angle, and hull curvature radius are generated and analyzed based on the robot's posture and steering motion. The mechanical properties of anti-slippage and anti-shedding under different motion states were studied so that the robot's critical point and limit adsorption force could be determined and verified. Simulation results show that the robot has good motion stability.

“Making Life Easier”: A Case Study Exploring the Development of Adaptive Apparel Design Innovations from a User-Centered Approach

Mindy Scheier, a former fashion designer and mother of a child with a disability, developed adaptive apparel design innovations focused on three categories: (a) magnetic closures; (b) adjustable pant legs, sleeves, and waistband; and (c) the flexibility of donning and doffing using different points of entry. The adaptive design features were incorporated into a first-of-its-kind adaptive children’s wear line collaboration with Tommy Hilfiger® in 2016. Scheier’s adaptive design features and her collaboration with Tommy Hilfiger® were well documented and have influenced additional adaptive apparel lines in mainstream fashion. The goal of this study was to gain an in-depth and contextualized understanding of Scheier’s design process to determine how she developed her adaptive apparel design innovations using a user-focused approach. To achieve this goal, a case study was deployed. This study revealed that Scheier included the PWD (people with disabilities) user in every stage of her design process by building trust and allyship with the PWD population. Further, Scheier had to balance the needs of the PWD user with that of the apparel industry to ensure her adaptive design features were included in mainstream apparel.

Adjustable leg harness for attaching tags to small and medium‐sized birds

Adjustable leg harness for attaching tags to small and medium‐sized birds

Optimised gynaecological examination with a new pelvic examination chair

ObjectiveThe present aim was to contribute to improving the traditional pelvic examination chair with vertical leg support and to evaluate patients’ and examiners’ experience of a new gyneacological and urological examination chair with heated upholstery. Study designA new gynaecological and urological examination chair was constructed with laterally adjustable leg support, a foot-plate and the perineum exposed only during the examination procedure. Patients (n = 131) with or without endometriosis were invited to participate in an anonymous questionnaire survey concerning how they experienced a gynaecological examination. Main outcome measuresThe patients and the gynaecologists who performed the examinations answered questionnaires evaluating the examination procedure in the traditional and in the new gynaecological and urological examination chair, respectively. The questionnaires asked about comfort, heating, integrity and the experience of pelvic examination with vertical or lateral leg support. The examination times were measured with a stop-watch. ResultsThe majority of the answers (n = 131) were significantly (p < 0.05–0.001) in favour of the new concept with lateral leg support and with increased comfort and integrity. The average examination time was significantly shortened and the patients more relaxed in the new gynaecological and urological examination chair. ConclusionThe traditional gynaecological chair with vertical leg support has remained basically unchanged for many years. The present study showed that the pelvic examination procedure can be significantly optimized with easy patient-friendly adaptations.

TIPPER FOR CONTROLLING FLOW BOXES OF POTATOES IN GRADING STATIONS

The main objectives of this study were to manufacture of tipper for controlling flow boxes of potatoes in grading stations of investment companies as alternate to the costly ( tenfold) of importing box tipper using the Egyptian facilities such as row material, local workshops and labors required with (one) tenth cost. While manufacturing of tipper take considered heavy duty different emptying angles of box tipper, 2,000kg lift as maximum lifting weight, single machine with twin hydraulic rams, Manual override in control panel, one set cradle inserts, adjustable height legs to give maximum height under conveyor of 1.6m, side safety guards, Light guards (not fitted when machine rose by 1.8m), Minimum cycle time 28 seconds and Manually adjustable flow door. Measuring indicators were tested for the local manufactured tipper at the tested emptying angles (degrees), hydraulic pressure (bar) and box capacity (ton). It was found that using the tested local tipper with emptying angle 1600 and 100 bar hydraulic pressure under 1.25 ton box capacity gave the best results in all treatment and achieving the minimum cycle time 28 seconds to empty the box and minimum bruises Therefore it is advisable to use the local manufacture tipper that showed the best results comparing the imported tipper that costing the tenfold compared to the local tipper and gave the same target

Automated Transitions Between Walking and Running in Legged Robots

This paper addresses the synthesis of controllers for walk-to-run transition (WRT) and run-to-walk transition (RWT) in legged robots with adjustable leg compliance. Inspired by human kinematics, we propose a detailed procedure for the WRT and RWT in an adjustable-stiffness spring and mass model, and derive control parameters that ensure effective gait transitions. The WRT is achieved by modulating the compliance of the leg in a piecewise constant way during the transition stride. In the RWT, in addition to the leg compliance, we modulate the touchdown angle of attack. The merits of the approach proposed are demonstrated via a simulation that incorporates the control of walking, followed by a transition to running with first increasing and then decreasing speed, and finally a transition back to walking.

Robust and efficient walking with spring-like legs

The development of bipedal walking robots is inspired by human walking. A way of implementing walking could be performed by mimicking human leg dynamics. A fundamental model, representing human leg dynamics during walking and running, is the bipedal spring-mass model which is the basis for this paper. The aim of this study is the identification of leg parameters leading to a compromise between robustness and energy efficiency in walking. It is found that, compared to asymmetric walking, symmetric walking with flatter angles of attack reveals such a compromise. With increasing leg stiffness, energy efficiency increases continuously. However, robustness is the maximum at moderate leg stiffness and decreases slightly with increasing stiffness. Hence, an adjustable leg compliance would be preferred, which is adaptable to the environment. If the ground is even, a high leg stiffness leads to energy efficient walking. However, if external perturbations are expected, e.g. when the robot walks on uneven terrain, the leg should be softer and the angle of attack flatter. In the case of underactuated robots with constant physical springs, the leg stiffness should be larger than in order to use the most robust gait. Soft legs, however, lack in both robustness and efficiency.

Simplified “on‐couch” daily quality assurance procedure for CT simulators

For most computed tomography (CT) simulators, radiation therapists must first remove the fat couch top in order to perform daily CT quality assurance (QA), and then use separate tools to perform localization‐laser QA. This process wastes time and effort, and creates the opportunity for accidents to occur. In this study, we tested a simple, yet comprehensive, daily QA program and phantom designed for CT simulators used in radiation oncology that would enable us to use only one tool to perform both laser and imaging QA on a fat couch. To construct a modified QA phantom, we attached three adjustable legs and fastened two metric scales (one vertically and one horizontally) to a commercial CT QA phantom. The adjustable legs helped to position and level the phantom conveniently in the needed position. The two metric scales were used for localization‐laser QA, while the phantom body was used for CT imaging QA. We evaluated five different CT scanners from two manufacturers with their designated couches to evaluate this phantom system. Since the couch is scanned along with the phantom, we evaluated the couch's effect on image quality. We found that the presence of the couch top changed the uniformity of water's CT number slightly, but did not change the visual image resolution. The couch top also produced different, yet reproducible, effects on image quality. The effects were greatest in the section of the phantom closest to the couch top. For a commercial carbon fiber couch top, the variation was within 3 Hounsfield Units (HU). The effect was couch‐ and scanner‐specific, and could be incorporated into the QA acceptability criteria for each CT scanner. By using the proposed QA program and phantom, we have been able to implement more thorough QA while decreasing the amount of effort and time the simulation therapists spend performing laser and imaging QA.PACS number(s): 87.55.Gh, 87.55.Qr, 87.56.Fc, 87.57.Q‐

SU‐FF‐J‐57: IBreathe: Monitoring Respiration with the Accelerometer in An IPod Touch

Purpose: The breathing pattern for respiration management is obtained by various methods, including infra‐red reflector monitored by a camera (RPM by Varian), spirometer (ABC by Elekta), belt connected to a bellows (4D‐CT by Phillips), or inductive belt (commonly used in sleep studies). We are exploring the use of the accelerometer in the widely available iPod‐Touch as a wireless device to monitor the breathing pattern for respiration management in radiation therapy. This device has wireless communication built into a compact form factor and powered by a battery. It can potentially be a convenient portable device for acquiring breathing patterns. Method and Materials: The iPod‐Touch has a three‐axis accelerometer so that it can detect the magnitude and direction of the local gravitational field relative to its housing. The angular resolution achievable is 0.1 degrees. The iPod‐Touch is placed on a Styrofoam platform with three adjustable legs for leveling. The platform is placed on the abdomen or chest of the patient, depending on the application. The change in inclination of the platform during respiration is detected by the accelerometer and recorded by the iPod‐Touch. For the current study, the recorded inclinations are sent as an attachment in an email for analysis. Results: Breathing traces of healthy subjects were acquired. The amplitude of the change in inclination corresponding to tidal volume was greater than 5 degrees peak‐to‐peak. The breathing trace was recorded at &gt;10 Hz. For a 10 breath‐per‐minute breathing cycle, there are &gt;60 recorded samples per breath. Conclusion: The accelerometer in an iPod‐Touch is sensitive enough to detect the breathing pattern and the recorded trace can be sent wirelessly for analysis. Further work will establish a wireless link between this device and a computer to continuously acquire real‐time breathing data. Supported in part by NIH P01‐CA59827.

The Design And Development Of Adjustable Prosthetic Device For A Leg Amputee Using A Six Bar Link Knee Mechanism

Using a six bar link knee mechanism an artificial adjustable leg is produced for an amputee. The prosthetic device when fitted to an amputee provided easy movement for the left leg amputee. It is produced using readily available materials involving aluminum, steel, polyethylene, leader, glue etc. the device has a special compared with other prosthetic leg devices in the market JORIND Vol. 4 (2) 2006: pp. 43-47

SU‐FF‐I‐55: A CT Daily Quality Assurance On‐Couch Procedure and Phantom in Radiation Oncology

Purpose: To design a simple yet comprehensive daily quality assurance (QA) program and phantom for CT Simulators in Radiation Oncology so that positioning laser and imaging QA can be performed on the flat couch using only one tool. This has been done to avoid removing the flat couch to perform CT QA and to simplify the daily QA procedure. Method and Materials: A new daily QA phantom was constructed by attaching to a commercially available CT QA phantom 3 adjustable legs and two metric scales in both vertical and horizontal directions. The two metric scales are used for laser QA, while the phantom body is used for CT imaging QA. Since the couch is scanned with the phantom, its effect on image quality was evaluated. The phantom is positioned on the couch such that couch effects are minimized. Four different GE CT scanners and 3 different Philips scanners were used to evaluate this phantom. Daily testing includes high and low contrast resolution, scale accuracy, CT number accuracy and uniformity. Results: The proposed program has been piloted in our institution. Inclusion of the couch produces different yet reproducible effects on image quality. The effects appear to be couch and scanner specific and are incorporated in the acceptability criteria for each CT scanner. Based on our data thus far, the presence of the couch does not change image resolution visually. It appears, however, that the couch causes changes in the uniformity of water's CT number. The effects are greatest in the section of the phantom closest to the couch. We thus limit our image quality evaluation to the central and 12 O'clock positions of the phantom. Conclusions: The proposed program and phantom has allowed us to implement a more comprehensive QA program while decreasing the level of effort by the simulation therapists.

Running in the real world: adjusting leg stiffness for different surfaces.

A running animal coordinates the actions of many muscles, tendons, and ligaments in its leg so that the overall leg behaves like a single mechanical spring during ground contact. Experimental observations have revealed that an animal's leg stiffness is independent of both speed and gravity level, suggesting that it is dictated by inherent musculoskeletal properties. However, if leg stiffness was invariant, the biomechanics of running (e.g. peak ground reaction force and ground contact time) would change when an animal encountered different surfaces in the natural world. We found that human runners adjust their leg stiffness to accommodate changes in surface stiffness, allowing them to maintain similar running mechanics on different surfaces. These results provide important insight into mechanics and control of animal locomotion and suggest that incorporating an adjustable leg stiffness in the design of hopping and running robots is important if they are to match the agility and speed of animals on varied terrain.

A remote controlled freeze corer for sampling unconsolidated surface sediments

A new coring device is presented which allows the recovery of loose watery surface sediments and the water/sediment interface by in situ freezing, resulting in well preserved samples. The instrument consists of a tripod with adjustable legs, a hydraulic system, an insulated thermos (with two electrical pumps), and a wedge-shaped freeze box. Alcohol chilled with dry ice is the freezing agent. The corer can be deployed from a boat or a raft and permits recovery of undisturbed surface sediment sections up to 100 cm long in deep waters. The corer is particularly useful for sampling varved sediments.

A remote controlled freeze corer for sampling unconsolidated surface sediments

A new coring device is presented which allows the recovery of loose watery surface sediments and the water/sediment interface byin situ freezing, resulting in well preserved samples. The instrument consists of a tripod with adjustable legs, a hydraulic system, an insulated thermos (with two electrical pumps), and a wedge-shaped freeze box. Alcohol chilled with dry ice is the freezing agent. The corer can be deployed from a boat or a raft and permits recovery of undisturbed surface sediment sections up to 100 cm long in deep waters. The corer is particularly useful for sampling varved sediments.

Sound reflecting shell tower and transporter structure and methods of erecting and storing the towers

An orchestra shell tower and tower transporter system has a plurality of shell towers comprising an acoustic central panel hingedly connected along its side edges to acoustic wing panels. A generally horizontally rearwardly extending tripod-shaped open base is fixed to the lower end of the central panel and counterweights both the central panel and the wing panels. Vertically adjustable dependent legs with stage engaging members are provided on the tower. A tower transporter has a forwardly extending tripod-shaped open base supported on caster wheels and configured to be received within the base of each of the shell towers. Vertically movable lifters on the transporter base have receptors for engaging the legs of each of the tower shells in lifting relationship and actuatable motors are provided on the transporter for raising and lowering the lifters, and thereby the tower engaged by the transporter for supporting the tower in a raised position for travel. The wing panels are fully folded after the shell tower reaches a position for storage and, as the successive towers are brought to the storage position, they are successively nested one with the other. Locking mechanism holds the tower wing panels in folded positions and in the user positions in which they substantially facially align with the central panel.

An angular alignment measurement device for prosthetic fitting

A device to measure socket/shank angular alignment in a prosthesis equipped with a Berkeley Adjustable Leg is described. Angular alignment in the sagittal plane can be measured over the entire 20-degree range with a repeatability of 1 degree. This device can be a useful prosthetics fitting, teaching, and research tool.

Comparative Assessment of Novel Sailing Trapeze Harness Designs

Prolonged trapezing during sailing often results in low back pain among elite sailors. Modifications of the trapeze harness have been proposed as one approach to ameliorating this problem. To evaluate six harnesses incorporating novel features that had tested well during pilot work, myoelectric activity was monitored at C5, T6, and L5 levels of sacrospinalis and at an abdominal site while five elite sailors wore the harnesses. Integrated EMG (IEMG) values were stored by a microcomputer at periodic intervals during each 10-min trial, as each subject maintained a static horizontal trapezing position in the laboratory. Factorial repeated-measures ANOVA indicated no change in IEMG values over time, but significant (p&lt;0.001) differences among harnesses at all four electrode sites. Features of trapeze harness design that appear to minimize muscular tension include heavy, rigid padding throughout the harness, full-length shoulder-to-buttocks support of the trunk, and adjustable leg strap supports as opposed to a crotch strap.

A Hand-Portable Single Nozzle Rainfall Simulator Designed for Use on Steep Slopes

The objective of this study was to develop a smaii plot (1 m*) rainfall simulator operational on steep terrain in the Guadalupe Mountains of New Mexico. The simuiator developed is bandportable and consists of a spray head assembly mounted on 3 adjustable legs. A 946-liter tank equipped with a gasoline powered pump was connected to the spray head assembly via rubber garden hoses. On steep slopes gravity provided sufficient pressure to operate the simulator. Site selection was limited to areas where the water tank could be located in a suitable upsiope position. The simuiator has been used for 2 years on 170 plots and has proved durable. Advantages of this device are the low cost of construction and operation, and the flexibility in plot-site selection it provides. The principal disadvantages are associated with the single stationary nozzle, such as uneven application of water at small drop sizes and low kinetic energies. An ideal rainfall simulator has yet to be developed. Those that most closely reproduce rainfall patterns and intensity are expensive and require large expenditures of manpower for setup and operation (Foster et al. 1979). However, rainfall simulators, even though imperfect, are essential tools for investigating hydrologic processes on arid and semiarid rangeland where rainfall events are sporadic. Simulator experiments can be used to estimate infiltration, interrili erosion runoff rates, and chemical water quality for given storm events. Impacts of range management practices (grazing strategy, brush control, reseeding) on the watershed can also be evaluated using rainfall simulators. Rainfall simulators can be used to collect data in a relatively short period, rather than the 10 to 20 years needed to collect sufficient information from natural rainfall events. Rainfall simulators also provide maximum control over plot conditions and rainfall characteristics. Rainfall simulators in common use by range watershed scientists are the mobile drop-forming (Blackburn et al. 1974), Rocky Mountain infiltrometer (Dortignac 1951) and versions of the Purdue type (Bertrand and Parr 1961). Ail the above provide mobility, but use of each is restricted to relatively flat terrain. Hand-portable infiltrometers have been developed (Adams et al. 1957, McQueen 1963, Seiby 1970, Munn and Huntington 1976, Malekuti and Gifford 1978) and are more suitable for rugged terrain. Munn and Huntington (1976) report the Tahoe Basin infiltrometer to be functional on slopes to 60%. Hand-portable infiltrometers, however, have not been widely used, perhaps because many are bulky, heavy, require pumps or motors, or have a limited water supply. This paper presents the construction, operation, rainfall characteristics, and limitations of a hand-portable small rainfall simulator developed for use on steep slopes in the Guadalupe Mountains of New Mexico.

A Simple and Economical Apparatus for Developing Thin-layer Chromatography Plates in the Anticircular Mode

Abstract An improved method for developing thin layer chromatography plates in the anticircular mode is described. The apparatus consists of two glass dishes arranged concentrically. The outer dish has a diameter of 98 mm × 15 mm deep, and the inner one a diameter of 92 mm × 13 mm deep. The inner dish rests on four small pieces of glass (5 × 5 × 2 mm). A paper wick, (16 mm wide × 1.5 mm thick) sits between the two dishes and transfers the solvent from the outer dish to the thin layer plates. The plate sits on the paper wick with the adsorbent facing down. To ensure an even solvent flow, the dishes are situated on a platform which has adjustable legs, and an horizontal level. Up to 50 samples can be analyzed on one 10 × 10 cm plate in 5 minutes. Less than 10 ml of solvent are needed.