Showing papers on "Stair climbing published in 2008"

Gait Synthesis and Sensory Control of Stair Climbing for a Humanoid Robot

Abstract: Stable and robust walking in various environments is one of the most important abilities for a humanoid robot. This paper addresses walking pattern synthesis and sensory feedback control for humanoid stair climbing. The proposed stair-climbing gait is formulated to satisfy the environmental constraint, the kinematic constraint, and the stability constraint; the selection of the gait parameters is formulated as a constrained nonlinear optimization problem. The sensory feedback controller is phase dependent and consists of the torso attitude controller, zero moment point compensator, and impact reducer. The online learning scheme of the proposed feedback controller is based on a policy gradient reinforcement learning method, and the learned controller is robust against external disturbance. The effectiveness of our proposed method was confirmed by walking experiments on a 32-degree-of-freedom humanoid robot.

Quantification of the probability of reaching mobility independence at discharge from a rehabilitation hospital in nonwalking early ischemic stroke patients: a multivariate study.

Abstract: Background: This study was designed to quantify the probability of recovery of mobility in admission nonwalking stroke survivors. Methods: We evaluated 437 of 500 consecutive patients admitted for sequelae of first ischemic stroke within the first month. We performed several logistic regressions using mobility status at discharge (independence in stair climbing; walking outside and inside, without aid or supervision; walking with cane or other aid, or need for wheelchair) as dependent variable, and several independent variables, including stratification of patients according to their Barthel Index (BI) score into 6 classes (≤10; 11–20; 21–30; 31–40; 41–50; 51–60). Results: At discharge, 4.58% of patients were independent in stair climbing, 8.70% were able to walk outside, 14.41% to walk inside, and 27.46% to walk with cane or other aid, while 44.85% remained in wheelchair. Very low BI scores at admission were associated with a high risk of need for wheelchair, whereas patients with BI score 51–60 showed a high probability to reach independence in stair climbing (OR = 5.60). Age, severity of neurological impairment, global aphasia, unilateral spatial neglect, male gender and vocational status also played a prognostic role. Conclusions: The probability of potential mobility recovery can be quantified at admission with better accuracy for independence in stair climbing and walking outside without any aid (percentages correctly predicted 95.4 and 91.8%, respectively). Stratification of BI score may be useful to better quantify the risk for each patient.

A Versatile Stair-Climbing Robot for Search and Rescue Applications

Abstract: For disaster mitigation as well as for urban search and rescue (USAR) missions, it is often necessary to place sensors or cameras into dangerous or inaccessible areas to get a better situation awareness for the rescue personnel, before they enter a possibly dangerous area. Robots are predestined to this task, but the requirements for such mobile systems are demanding. They should be quick and agile and, at the same time, be able to deal with rough terrain and even to climb stairs. The latter is always required if the rescue personnel has to get access to higher floors inside a building. A rugged, waterproof and dust-proof corpus, and, if possible, the ability to swim, are only a few of many requirements for such robots. With those requirements in mind, the hybrid legged-wheeled robot ASGUARD was developed. This robot is able to cope with stairs, very rough terrain, and is able to move fast on flat ground. We will describe a versatile adaptive controller, based only on proprioceptive data. An additional inclination feedback is used to make the controller versatile for flat ground as well as for steep slopes and stairs. An attachable float provided, the robot is able to swim, using the same locomotion approach. By using twenty compliant legs, which are mounted around four individually rotating hip-shafts, we use an abstract model of quadruped locomotion. For the control design, four independent pattern generators are used. In contrast to many other hybrid legged-wheeled robots, we use the direct proprioceptive feedback in order to modify the internal control loop, thus adapting the model of the motion pattern. For difficult terrains, like slopes and stairs, we use a phase-adaptive approach which is using directly the proprioceptive data from the legs.

Biomechanics Effects of Kinesio Taping for Persons with Patellofemoral Pain Syndrome During Stair Climbing

Abstract: Purpose The purpose of this study was to examine the biomechanical effects of kinesio taping for persons with patellofemoral pain syndrome during stair climbing. Methods- Fifteen women diagnosed with PFPS by an experienced musculoskeletal physiotherapist were recruited and exclusion criteria were based on previous studies. Ten normal subjects were recruited as control group in this study. The ground reaction forces (GRFs) and the EMG activity timing and ratio of VMO and VL were calculated for no tape, placebo tape, and kinesio taping conditions for PFPS and control groups during ascending and descending stair.

A Stairway Detection Algorithm based on Vision for UGV Stair Climbing

Abstract: In the paper, we present a vision based algorithm used to guide the unmanned ground vehicles (UGV) for autonomous stairways climbing and implement it on UGV successfully. The reliability of guiding UGV to climb stairs requires evaluating two offset parameters: the position of vehicle on stairs and the orientation angle to stairs. The intention of our algorithm is to estimate these two parameters through extracting the stair edges robustly. To achieve this goal, we apply the Gabor filter to eliminate the influence of the illumination and keep edges, and propose a fast method to remove small lines. Finally we link stair edges, and estimate the offset parameters used to steer the vehicle by RANSAC algorithm. Experiments on various stairways including indoor and outdoor are given in various light conditions. The results validate our algorithm.

Pedometer Accuracy During Stair Climbing and Bench Stepping Exercises

Abstract: The purpose of the present investigation was to examine pedometer accuracy during stair climbing and descending as well as during the performance of a bench stepping exercise. Ten healthy men participated in the present investigation. All subjects ascended and descended an 18 cm high public staircase, and performed a bench stepping exercise by using a 10, 20 and 30 cm high platforms, while wearing three different commercial pedometers (DW-800, YM, HJ- 700IT; OM, Lifecorder; KZ). In both situations, the stepping rate was controlled at 40, 50, 80, 100 and 120 steps·min-1. The pedometer scores tended to underestimate the actual number of steps during stair climbing with a slower stepping rate and/or the lower height of a platform. During the stair ascending and descending and the bench stepping exercise using 20 to 30 cm high platforms at 80 to 120 steps·min-1, the magnitude of the measurement error was -3.8 ± 10. 8 % for KZ, -2.1 ± 9.8 % for YM and -11.0 ± 18.9 % for OM. These results indicate that the KZ and the YM can accurately assess the number of steps during stair climbing using 20 to 30 cm high platforms at 80 to 120 steps·min-1. Key points Pedometers can assess the number of step accurately within an acceptable range of measurement error during the stair climbing activities at a stepping rate of 80 step·min-1 or faster with 18 cm or higher stairs.

In vitro fatigue failure of cemented acetabular replacements: a hip simulator study.

Abstract: Although hip simulators for in vitro wear testing of prosthetic materials used in total hip arthroplasty (THA) have been available for a number of years, similar equipment has yet to appear for endurance testing of fixation in cemented THA, despite considerable evidence of late aseptic loosening as one of the most significant failure mechanisms in this type of replacements An in vitro study of fatigue behavior in cemented acetabular replacements has been carried out, utilizing a newly developed hip simulator The machine was designed to simulate the direction and the magnitude of the hip contact force under typical physiological loading conditions, including normal walking and stair climbing, as reported by Bergmann et al (2001, Hip 98, Freie Universitaet, Berlin) A 3D finite element analysis has been carried out to validate the function of the hip simulator and to evaluate the effects of boundary conditions and geometry of the specimen on the stress distribution in the cement mantle Bovine pelvic bones were implanted with a Charnley cup, using standard manual cementing techniques Experiments were carried out under normal walking and descending stairs loading conditions with selected load levels from a body weight of 75-125 kg Periodically, the samples were removed from the test rigs to allow CT scanning for the purpose of monitoring damage development in the cement fixation The hip simulator was found to be satisfactory in reproducing the hip contact force during normal walking and stair climbing, as reported by Bergmann et al Finite element analysis shows that the stress distributions in the cement mantle and at the bone-cement interface are largely unaffected by the geometry and the boundary conditions of the model Three samples were tested up to 17 x 10(6) cycles and sectioned post-testing for microscopic studies Debonding at the bone-cement interface of various degrees in the posterior-superior quadrant was revealed in these samples, and the location of the failures corresponds to the highest stressed region from the finite-element analysis Preliminary experimental results from a newly developed hip simulator seem to suggest that debonding at the bone-cement interface is the main failure mechanism in cemented acetabular replacements, and descending stairs seem to be more detrimental than normal walking or ascending stairs with regard to fatigue integrity of cement fixation

Autonomous stair climbing algorithm for a small four-tracked robot

Abstract: In outdoor environments, mobility, adaptability and reliability of a robot are more important than its speed and precise trajectory. From a practical point of view, tracked robots have an advantage over wheeled robots in outdoor applications. The tracked robot is frequently operated by using the remote controller, but the remote operation is not effective for all cases. To overcome some complex obstacles such as rocks or stairs, the information related to the robot posture is required. However, the sensor information is not intuitive to the user to control the robot. In this research, a multi-active crawler robot (MACbot) was developed and the autonomous stair climbing algorithm was implemented to deal with those problems. Various experiments show that the MACbot can climb the stair autonomously.

Gaze Control and Foot Kinematics During Stair Climbing: Characteristics Leading to Fall Risk in Progressive Supranuclear Palsy

Abstract: Background and Purpose: Does gaze control influence lower-extremity motor coordination in people with neurological deficits? The purpose of this study was to determine whether foot kinematics during stair climbing are influenced by gaze shifts prior to stair step initiation. Subjects and Methods: Twelve subjects with gaze palsy (mild versus severe) secondary to progressive supranuclear palsy were evaluated during a stair-climbing task in a cross-sectional study of mechanisms influencing eye-foot coordination. Infrared oculography and electromagnetic tracking sensors measured eye and foot kinematics, respectively. The primary outcome measures were vertical gaze fixation scores, foot lift asymmetries, and sagittal-plane foot trajectories. Results: The subjects with severe gaze palsy had significantly lower lag foot lift relative to lead foot lift than those with a mild form of gaze palsy. The lag foot trajectory for the subjects with severe gaze palsy tended to be low, with a heading toward contact with the edge of the stair. Subjects with severe gaze palsy were 28 times more likely to experience “fixation intrusion” (high vertical gaze fixation score) during an attempted shift of gaze downward than those with mild ocular motor deficits (odds ratio [OR]=28.3, 95% confidence interval [CI]=6.4–124.8). Subjects with severe gaze shift deficits also were 4 times more likely to have lower lag foot lift with respect to lead foot lift than those with mild ocular motor dysfunction (OR=4.0, 95% CI=1.7–9.7). Discussion and Conclusion: The small number of subjects and the variation in symptom profiles make the generalization of findings preliminary. Deficits in gaze control may influence stepping behaviors and increase the risk of trips or falls during stair climbing. Neural and kinematic hypotheses are discussed as possible contributing mechanisms.

Mechanical behaviour of a prosthesized human femur: a comparative analysis between walking and stair climbing by using the finite element method

Abstract: The aim of this study is to perform finite element investigation of the mechanical behaviour of a prosthesized human femur during walking and stair climbing. Such activities are in fact encountered with the highest frequencies during daily living. In order to numerically analyze the stress shielding of the femoral bone with an artificial hip replacement, the strain and stress distributions both in the femur and in the stem were evaluated by using the finite element method. From a set of CT images the geometry of the femur was recovered and meshed. An operation of virtual surgery allowed to insert the metal stem (constructed by a CAD code) in the medullary canal. Numerical simulations showed evidence that, when comparing walking with stair climbing for stresses and strain energy density, maxima and minima values change dramatically, even if the localizations remain the same ones. Furthermore, for each type of daily activity, the unloading of bone tissue is confirmed in the case of prosthesized femur with respect to the physiological one, and hence the well-know phenomenon of stress shielding is exhibited. The development of a computational model allowed to deal with the complexity of the biomechanical problem and to describe quantitatively the mechanical behaviour of bone tissue in contact with the metal stem. The calculated results motivate the performed analyses because they are sufficient to activate the mechanisms of deposition and resorption in the bone tissue at contact with the artificial biomaterial. Thus, stair climbing confirms to be a critical task for primary stability of the prosthesized femur with respect to the activity of walking.

Muscle coordination in healthy subjects during floor walking and stair climbing in robot assisted gait training

Abstract: The aim of gait rehabilitation is a restoration of an independent gait and improvement of daily life walking functions. Therefore the specific patterns, that are to be relearned, must be practiced to stimulate the learning process of the central nervous system (CNS). The Walking Simulator HapticWalker allows for the training of arbitrary gait trajectories of daily life. To evaluate the quality of the training a total of 9 subjects were investigated during free floor walking and stair climbing and during the same tasks in two different training modes on the HapticWalker: 1) with and 2) without vertical center of mass (CoM) motion. Electromyograms (EMG) of 8 gait relevant muscles were measured and muscle activation was compared for the various training modes. Besides the muscle activation as an indicator for the quality of rehabilitation training the study investigates if a cancellation of the vertical CoM movement by adaption of the footplate trajectory is feasible i.e. the muscle activation patterns for the two training modes on the HapticWalker agree. Results show no significant differences in activation timing between the training modes. This indicates the feasibility of using a passive patient suspension and emulate the vertical CoM motion by trajectory adaption of the footplates. The muscle activation timing during HapticWalker training shows important characteristics observed in physiological free walking though a few differences can still remain.

A stairway detection algorithm based on vision for UGV stair climbing

Abstract: In the paper, we present a vision based algorithm used to guide the Unmanned Ground Vehicles (UGV) for autonomous stairways climbing and implement it on UGV successfully. The reliability of guiding UGV to climb stairs requires evaluating two offset parameters: the position of vehicle on stairs and the orientation angle to stairs. The intention of our algorithm is to estimate these two parameters through extracting the stair edges robustly. To achieve this goal, we apply the Gabor filter to eliminate the influence of the illumination and keep edges, and propose a fast method to remove small lines. Finally we link stair edges, and estimate the offset parameters used to steer the vehicle by RANSAC algorithm. Experiments on various stairways including indoor and outdoor are given in various light conditions. The results validate our algorithm.

Stair-climbing wheeled vehicle

Abstract: A wheeled vehicle comprising a power-driven spider assembly for ascending and descending stairs. The vehicle includes an angular position sensor providing input to a controller operable to control a servo-motor to effectively lock the position of the spider relative to the frame, regardless of the hand truck's spatial orientation relative to a vertical plane, or any balancing of the hand truck. The angular position sensor provides input to the controller, which is programmed with predefined angular zones of instability, and causes the controller to accelerate rotation of the spiders through those zones when the wheeled vehicle is in the descent mode, to avoid instability of the hand truck. A hand truck may include a removable basket and/or a pivotable platform usable to transport loads.

Haptic control methodologies for telerobotic stair traversal

Abstract: Teleoperated mobile robots provide the ability for a human operator to safely explore and evaluate hazardous environments. This ability represents an important progression towards the preservation of human safety in the inevitable response to situations such as terrorist activities and urban search and rescue. The benefits of removing physical human presence from such environments are obvious, however challenges inhibiting task performance when remotely operating a mobile robotic system need to be addressed. The removal of physical human presence from the target environment introduces telepresence as a vital consideration in achieving the desired objective. Introducing haptic human-robotic interaction represents one approach towards improving operator performance in such a scenario. Teleoperative stair traversal proves to be a challenging task when undertaking threat response in an urban environment. This article investigates the teleoperation of an articulated track mobile robot designed for traversing stairs in a threat response scenario. Utilising a haptic medium for bilateral human-robotic interaction, the haptic cone methodology is introduced with the aim of providing the operator with a vision-independent, intuitive indication of the current commanded robot velocity. The haptic cone methodology operates synergistically with the introduced fuzzy-haptic augmentation for improving teleoperator performance in the stair traversal scenario.

Routine stair climbing in place of residence and body mass index: a pan-European population based study.

Abstract: Routine stair climbing in place of residence and Body Mass Index: a pan-European population based study

A robotic biarticulate leg model

Abstract: Biarticulate muscles have been shown to perform the function of power transfer from the upper to lower leg, such as in tasks such as running, jumping, and stair climbing. A new robotic model of the human leg is described. This robotic leg transfers power from motors on the hip to the ankle. The importance of timing in maximizing the force transfer to push off at the toe is explored.

Design and implementation of a stair-climbing robot

Abstract: Taiwan and other developed countries have being experienced an emergence of a growing aging population. Home-caring robot is an excellent candidate capable of supporting such an aging society. In the paper, a robot is designed to move up-and-down stairs to provide service for the elders. The robot consists of a main body for moving, a front arm and a rear arm for moving up and down stairs. The main body is equipped with two brushless dc motors (BLDCMs) and their drives for locomotion, worm gears for torque amplification, two dc motors to control two arms, and DSP-based board as control center. The robot is equipped with roller chains attached with rubber blocks used to generate friction with ground and stairs for moving. The distance between any two rubber blocks is properly arranged to fix the stair brink. The moving direction of the robot is steered based on the speed difference of two BLDCMs and the information from ultrasonic sensors. A walking experiment of moving up and down stairs with the rise of 120 mm and depth of 400 mm is shown in the video.

Development Image Processing Technique for Climbing Stair of Small Humaniod Robot

Abstract: A major research of the climb stair small humanoid robot is to make a robot can climb stair with itself. To climb stair, the robot needs to find the environment information. This paper presents the new technique for climb stair robot using image processing technique and also reduces the time processing. The experiment had been used a single camera fix at 60 cm height on the top of robot. The robot positions are located 60 and 55 cm away from the stair. The results show that, this technique can be applied to solve the problem of a robot climb stair, which the robot do not needed to climb at the middle of stair. The result also shows this technique can reduce the time computation approximately 48%.

Development of a stair-climbing robot using springs and planetary wheels

Abstract: This paper presents a self-propelled travelling mechanism capable of climbing stairs without a sensor or judging algorithm. The developed leg-wheeled mobile robot, which is a type of mechanism to b...

Stair Climbing Aid

Abstract: A stair climbing aid comprises two slide rails, an assist member, a control mechanism and two positioning assemblies. The slide rails and the assist member are assembled to handrails at both sides of the stairs. The control mechanism is disposed on the assist member to be controlled by the user. The positioning assemblies are disposed at both sides of the assist member, each positioning assembly is provided with an engaging portion to be engaged in the respective positioning portions of the slide rail. Thereby, an anti-slide effect is produced, so as to prevent the user from falling down the stairs and to help the user move from step to step safely.

Effects of point-of-choice stair climbing interventions in Hong Kong.

Abstract: One simple way to achieve the current recommendations is to accumulate walking throughout the day. An additional way to further this aim is to accumulate stair climbing. Like walking, stair climbing requires no equipment and is freely available, at least in the developed world. Unlike walking, however, stair climbing is physiologically vigorous, requiring 9.6 times more energy than the resting state.2 As obesity prevention is a major aim of physical activity promotion, the high energy expenditure of stair climbing can improve the balance between energy intake and expenditure. For example, an 80-kg man climbing a typical 3-m flight of stairs 10 times a day would expend approximately 27.5 Kcals a day, equating to 10 038 Kcals over a year, an energy expenditure equivalent to about 4 days worth of food.3 From an energy expenditure perspective, the speed at which the stairs are climbed is of minimal importance; energy is expended in raising one’s weight against gravity. Thus low levels of fitness, a common barrier to exercise in the overweight, are not a barrier to stair climbing. Indeed a recent worksite intervention revealed a greater response in overweight employees suggesting that stair climbing may be an acceptable type of physical activity for overweight individuals.3

Muscle activation of stroke patients during stair climbing in robot assisted gait training

Abstract: For central nervous system (CNS) impaired patients, e.g. after stroke, the achievement of an independent, stable gait function and endurance in walking is essential for independent mobility in daily life. Modern concepts of rehabilitation favor a task specific repetitive training, that facilitates natural motion and muscle activation patterns, i.e. in addition to commonly practiced floor walking other gait motions of daily living (ADL), such as stair climbing, should be trained. In gait rehabilitation of severely affected non-ambulatory patients, a guided training must be applied as no or only little voluntary motor control is left in the affected side. The rehabilitation robot HapticWalker is the first device that allows for robot assisted guided training of arbitrary foot trajectories, e.g. also stair climbing. The goal of this study was to assess the effect of guided training in stair climbing condition on the HapticWalker on the movement and muscle activation patterns of stroke patients. Generally rhythmic and phasic muscle activation patterns were observed, which is an important factor in gait rehabilitation. The training of stair climbing condition on the HapticWalker also facilitated body weight shift in all patients and proper activation of weight bearing muscles. The HapticWalker currently lacks a lateral hip guidance facility, hence individual differences in the ability of controlling hip movement and body weight shift depending on the level of gait ability were observed.