Showing papers on "Stair climbing published in 2010"

Innovative gait robot for the repetitive practice of floor walking and stair climbing up and down in stroke patients.

Abstract: Stair climbing up and down is an essential part of everyday's mobility. To enable wheelchair-dependent patients the repetitive practice of this task, a novel gait robot, G-EO-Systems (EO, Lat: I walk), based on the end-effector principle, has been designed. The trajectories of the foot plates are freely programmable enabling not only the practice of simulated floor walking but also stair climbing up and down. The article intended to compare lower limb muscle activation patterns of hemiparetic subjects during real floor walking and stairs climbing up, and during the corresponding simulated conditions on the machine, and secondly to demonstrate gait improvement on single case after training on the machine. The muscle activation pattern of seven lower limb muscles of six hemiparetic patients during free and simulated walking on the floor and stair climbing was measured via dynamic electromyography. A non-ambulatory, sub-acute stroke patient additionally trained on the G-EO-Systems every workday for five weeks. The muscle activation patterns were comparable during the real and simulated conditions, both on the floor and during stair climbing up. Minor differences, concerning the real and simulated floor walking conditions, were a delayed (prolonged) onset (duration) of the thigh muscle activation on the machine across all subjects. Concerning stair climbing conditions, the shank muscle activation was more phasic and timely correct in selected patients on the device. The severely affected subject regained walking and stair climbing ability. The G-EO-Systems is an interesting new option in gait rehabilitation after stroke. The lower limb muscle activation patterns were comparable, a training thus feasible, and the positive case report warrants further clinical studies.

floor walking and stair climbing up and down in stroke patients

Abstract: Background: Stair climbing up and down is an essential part of everyday's mobility. To enable wheelchair-dependent patients the repetitive practice of this task, a novel gait robot, G-EO-Systems (EO, Lat: I walk), based on the end-effector principle, has been designed. The trajectories of the foot plates are freely programmable enabling not only the practice of simulated floor walking but also stair climbing up and down. The article intended to compare lower limb muscle activation patterns of hemiparetic subjects during real floor walking and stairs climbing up, and during the corresponding simulated conditions on the machine, and secondly to demonstrate gait improvement on single case after training on the machine. Methods: The muscle activation pattern of seven lower limb muscles of six hemiparetic patients during free and simulated walking on the floor and stair climbing was measured via dynamic electromyography. A non-ambulatory, sub-acute stroke patient additionally trained on the G-EO-Systems every workday for five weeks. Results: The muscle activation patterns were comparable during the real and simulated conditions, both on the floor and during stair climbing up. Minor differences, concerning the real and simulated floor walking conditions, were a delayed (prolonged) onset (duration) of the thigh muscle activation on the machine across all subjects. Concerning stair climbing conditions, the shank muscle activation was more phasic and timely correct in selected patients on the device. The severely affected subject regained walking and stair climbing ability. Conclusions: The G-EO-Systems is an interesting new option in gait rehabilitation after stroke. The lower limb muscle activation patterns were comparable, a training thus feasible, and the positive case report warrants further clinical studies.

Review Article: Increasing physical activity with point-of-choice prompts--a systematic review.

Abstract: Aims: Stair climbing is an activity that can easily be integrated into everyday life and has positive health effects. Point-of-choice prompts are informational or motivational signs near stairs and...

To what extent does leg length discrepancy impair motor activity in patients after total hip arthroplasty

Abstract: The aim of this study was to evaluate the effects of limb lengthening up to 20 mm after THA on symmetry of hip kinematics and kinetics during common activities of daily living. Twenty patients (age range 49–80 years) operated on with Link Lubinus II THA, with lateral access and a mean follow-up of 16 months, were assessed by gait analysis during level walking, stair ascending and descending. The time-distance, hip kinetics and kinematics values were statistically compared between the operated side and the non-operated side in order to assess symmetry. The 12-item Questionnaire was used to assess satisfaction and personal perception of limb lengthening. Mean value of limb lengthening after THA was 11 mm (SD 6). Minor abnormalities were found in the kinematics and kinetics of the operated and non-operated hips during level walking and stair climbing. The score of the questionnaire corresponded to a high level of satisfaction after THA and only two patients complained of limping independent from the amount of discrepancy. From this study we can conclude that a leg length inequality in the range of 1–20 mm does not impair the symmetry of time–distance parameters and of hip kinematics and kinetics during gait and stairs walking. Although objective, gait analysis data did not correspond to patient’s perception of discrepancy, which is subjective and irrespective of the amount of lengthening. There is biomechanical evidence that a limb lengthening of up to two centimetres after THA in general does not need to be corrected by means of a contralateral shoe lift. Individual decisions to the contrary need to be justified.

Accuracy of six minute walk test, stair test and spirometry using maximal oxygen uptake as gold standard

Abstract: PURPOSE: To assess the accuracy of the variables stair climbing time (SCt), stair climbing power (SCP), six-minute walk test distance (6MWT), and forced expiratory volume in 1 second (FEV1) using maximal oxygen uptake on exercise (VO2max) as the gold standard. METHODS: Tests were performed in 51 patients. FEV1 was measured by spirometry and 6MWT was performed in a flat 120-m corridor. Stair climbing test was performed on a 6-flight stairway to obtain SCt and SCP. VO2max was measured by ergospirometry, using the Balke protocol. Pearson's linear correlation and p values were calculated between VO2max and the other variables tested. For accuracy calculations, variable cutoff points were obtained through receiver operating characteristic (ROC) curves, dividing individuals into normal or unhealthy. Kappa statistic was used to calculate concordance. RESULTS: Accuracy was: SCt - 86%, 6MWT - 80%, SCP - 71%, FEV1(L) - 67%, FEV1(%) - 63%. SCt and 6MWT showed 93.5% sensitivity when combined in parallel, and 96.4% specificity in series. CONCLUSION: SCt presented the best accuracy. SCt and 6MWT combined showed nearly 100% sensitivity or specificity. Thus, these simple exercise tests should be more routinely used, especially when an ergospirometer is not available to measure VO2max.

Configuration and tip-over stability analysis for stair-climbing of a new-style wheelchair robot

Abstract: In this paper, a wheelchair robot equipped with new-style variable-geometry-tracked mechanism is proposed. This new-style mechanism can adapt to convex terrain and turn to concave geometry by active control of track tension, based on which the terrain adaptability of the wheelchair robot is improved. Aiming at climbing stairs, the transformation rule of robot configuration is presented, the description of passenger's attitude and action is established. Following that, the tip-over stability analysis and simulation are performed with Force-Angle stability measure, and the variation of the tip-over stability margin of the robot under different conditions of passenger's attitude and action during stair-climbing is obtained. The analysis and simulation results provide a valid reference to the wheelchair robot's potential application.

Gait rehabilitation system for stair climbing and descending

Abstract: This paper describes the development of a gait rehabilitation system with a locomotion interface (LI) for stair climbing or descending. The LI consists of two 2 DOF manipulators equipped with footpads. These can move the user's feet while his or her body remains stationary. The footpads follow the prerecorded motion of the feet of a healthy individual. For gait training, the user progresses iteratively through successively more advanced modes. In this study, three modes, enforced stair climbing/descending, semi-voluntary stair climbing/descending, and real stair climbing/descending were used. Comparisons were made between the modes for healthy individuals and a patient. The effectiveness of the system was examined using EMG and foot pressure data.

Outdoor stairway segmentation using vertical vanishing point and directional filter

Abstract: In this paper we propose to detect the localization and recognition of outdoor stairway. This problem is the most fundamental step in solving the problem of autonomous stair climbing navigation. An autonomous system must be able to recognize parameters that can describe stairways in unknown environments. First, we proposed to extract the longest segments of diagonal lines from the edge image in order to identify a set of diagonal line segments candidate. This can provide information itself. Based on the vanishing point we defined the area where the stair candidate is located. We then applied the Gabor filter to detect the horizontal line. Finally, after combining the previous two steps, the algorithm defined the candidate stair area in the image. A set of stair images were used within a variety of conditions in our proposed method. As a result, testing was able to prove its effectiveness.

Promoting stair climbing in Barcelona: similarities and differences with interventions in English-speaking populations.

Abstract: This study evaluated the ability of three different messages to encourage stair climbing on the Barcelona underground. Two weeks of baseline were followed by three banner intervention periods with three different messages, each for a 2 week period. Follow-up data was gathered two weeks after removing the messages. Stair climbing increased overall [odds ratio (OR) = 1.45; 95% confidence intervals (CIs) = 1.25–1.68], with no statistical differences between the messages. During follow-up, stair climbing remained elevated (OR = 1.22; 95% CIs = 1.01–1.48). These preliminary data suggest stair climbing interventions, effective in the UK, may prove successful in Catalonia and Spain. Baseline differences, however, outline the magnitude of the task.

Low-technology exercise test in the preoperative evaluation of lung resection candidates.

Abstract: Exercise tests are increasingly used in the preoperative functional evaluation of lung resection candidates. Low-technology exercise tests include six minute walking, shuttle walking and stair climbing. Conflicting evidence has been reported regarding 6 minute walking test. This test should not be used to select patients for lung resection. An incremental shuttle walk test is easier to replicate than 6 minute walking test. Most patients achieving 25 shuttles or 400 m have a maximum oxygen consumption measured at cardiopulmonary exercise test greater than 15 l/Kg/min. Although this test tends to underestimate performance at the lower range compared to peak oxygen consumption it can be used a screening test before lung resection. Excluding patients from operation based on this test alone is however not recommended and a formal cardiopulmonary exercise test should be always used in those walking less than 400 m. Stair climbing has been extensively studied in thoracic surgery. Several studies have found that poor performance in this test is indicative of cardiopulmonary complications and mortality after lung resection. In particular, climbing less than 12 m represents very high risk, whereas climbing more than 22 m is associated with a favourable outcome. Recent guidelines recommend referring all patients climbing lower than 22 m to cardiopulmonary exercise test. Stair climbing can be used as a screening test in cases cardiopulmonary exercise test is not readily available. In general, patients climbing more than 22 m can proceed to surgery without further evaluation.

An informational stair climbing intervention with greater effects in overweight pedestrians

Abstract: Previous interventions have successfully increased levels of stair climbing in public-access settings (e.g. malls). This study used robust methods to establish the magnitude of intervention effects among a specific target group—the overweight. Ascending stair/escalator users (N 5 20 807) were observed in a mall. A 2-week baseline was followed by a 5-week intervention in which message banners, promoting stair climbing, were attached to the stair risers. Standardized silhouettes were used to code individuals as normal/overweight. Logistic regression analyses were conducted with stair/escalator choice as the outcome variable and weight status entered as a moderator alongside condition, gender, ethnicity and ‘pedestrian traffic volume’. Overall, the intervention significantly increased the rate of stair climbing [odds ratio (OR) 5 1.28, 95% confidence intervals (CI) 5 1.08‐1.53], with the effects sustained over 5 weeks. There were differential effects between weight categories, with greater increases in overweight (OR 5 1.95, CI 5 1.34‐2.83) versus normal weight individuals (OR 5 1.29, CI 5 1.09‐1.53). In conclusion, message prompts produced larger effects among overweight individuals, who could benefit most from stair climbing. The public health value of these interventions may, therefore, be greater than realized. The heightened effects among the overweight were likely due to the salience of the current message, which linked stair climbing with the target of weight control.

Stair Climbing Wheel with Multiple Configurations

Abstract: A stair climbing wheel and vehicles are described The stair climbing wheel has a rolling wheel and a plurality of deployable protrusions that allow the wheel to climb stairs The deployable protrusions can be deployed from or retracted into the rolling wheel In the retracted position, the stair climbing wheel functions as a traditional circular wheel These stair climbing wheels can be incorporated on a wide variety of vehicles, such as hand trucks, wheelchairs, and personal transports to allow these vehicles to climb stairs

Wheel & Track hybrid robot platform for optimal navigation in an urban environment

Abstract: Various robot platforms are used for tasks in a variety of disaster fields. For public safety in some urban environments, a novel wheel and track hybrid robot platform which is able to perform fast navigation in flatland and stairs is developed. For its applicability on various environments, we devised a transformable track structure which can climb stairs and navigate the flat floor rapidly. The transformable track can transfer the power with three actuators. Track arms installed in front, rear, and side are used for mode change between floor-navigation and stair-climbing. When the robot navigates on a flatland, tracks on its left and right side are down-folded and kept up folded posture in which four wheels are exposed to the outside of tracks. In this floor-navigation mode, the robot fast navigates flat floors without contact between tracks and the floor. When the robot ascends stairs, the robot spreads tracks until they enclose four wheels. In the stair-climbing mode, two tracks are working. The wheel and track hybrid robot platform was verified by real-navigation experiments in some indoor test-bed environments. The experimental result shows that the developed robot platform has good performance in climbing stair with two tracks and navigating flatland. The platform's maximum speed on flatland is 7.2 km/h and its maximum slope to climbing is an angle of 45 degrees.

The metabolic and muscular differences between two stair-climbing strategies of young adults.

Abstract: When climbing stairs, there are 2 practical strategies, contact each step with alternating feet (single) or contact every other step (double) with alternating feet. Our purpose was to evaluate the metabolic cost and muscular activity of these single and double stair-climbing strategies. We hypothesized that metabolic cost would not differ between the 2 strategies, because the subjects would complete the 2 protocols with a similar speed that would minimize cost. Likewise, we hypothesized that muscle activity during stance would not differ between the 2 stepping strategies. Twelve subjects completed baseline and experimental protocols. For the baseline protocol, the subjects walked up a stairwell with a single-step and a double-step strategy. For the experimental protocol, each subject walked on a treadmill inclined to the same degree as the stairs at the speed and step frequency determined from the baseline protocol. Every subject completed the baseline testing with a faster average speed during the double-step protocol. After mimicking each strategy with our experimental methods, we calculated that the double-step strategy would yield a greater use of metabolic energy, equal to approximately 1.0-1.3 kcalxkg-1xh-1, on average 70-90 additional kcalxh-1. This double-step strategy required a greater activity for propulsion during stance for the ankle and knee extensors. In summary, to maximize metabolic cost and muscular activity, we recommend a double-stair-climbing (skip a step) strategy.

A comparison of human and canine kinematics during level walking, stair ascent, and stair descent

Abstract: Summary Stair ambulation is sometimes unavoidable for humans and canines, and changes several parameters of the gait cycle in comparison to level walking. The purpose of this paper is to review and investigate stair ambulation kinematics and kinetics for the human and canine when compared with gait on level surfaces. Data collected from 2 laboratories in a similar manner were analyzed to compare the ankle (tarsal) joint, knee (stifle) joint, and hip joint kinematics for level walking, stair ascent, and stair descent in dogs and humans. The comparison of humans and dogs reveals humans use a greater overall range of motion (ROM) in the hip and knee compared to dogs in all tasks. Dogs use a much greater ROM in the ankle or tarsal joint compared to humans in all tasks. The decreased amount of ROM used at the hip and stifle joints of dogs during level gait, stair climbing, and stair descent when compared to humans is likely a direct result of the increased amount of tarsal flexion dogs use when compared to people. This paper identifies the peak angles of flexion and extension, overall ranges of motion of the hindlimb during normal walking, stair ascent and descent. This information may be used to help devise rehabilitation programs for dogs that need to increase the motion in a particular hindlimb joint through targeted movement tasks. Schlusselworter: Biomechanik, Kinematik, Hund, Mensch, Treppensteigen.

On Design and Development of an Intelligent Mobile Robotic Vehicle for Stair-Case Navigation

Abstract: The present chapter focuses on the study of different features of stair-climbing mechanisms for transporting materials autonomously. The authors finally concentrate on arm wheel-based design for stair climbing. An attempt is made to design, develop and construct a mobile robotic vehicle for stair navigation with the following functional attributes: (i) motion on plane surface, (ii) navigation on stair- case, i.e., ascending and descending stairs keeping payload carrier platform parallel to the ground, (iii) autonomous navigation and control including obstacle avoidance and stair detection. The authors attempt to design a skid steer model incorporating the slip-friction for motion on plane surface and sensor-based navigation on stair-case and plane surface. It encompasses necessary controls including vision-assisted controller for stair-case detection and sonar data-based two layered fuzzy logic technique for obstacle avoidance.

Design, simulation and manufacturing of a Tracked Surveillance unmanned ground vehicle

Abstract: This paper describes design, Simulation and manufacturing procedures of HIRAD - a teleoperated Tracked Surveillance UGV for military, Rescue and other civilian missions in various hazardous environments. A Double Stabilizer Flipper mechanism mounted on front pulleys enables the Robot to have good performance in travelling over uneven terrains and climbing stairs. Using this Stabilizer flipper mechanism reduces energy consumption while climbing the stairs or crossing over obstacles. The locomotion system mechanical design is also described in detail. The CAD geometry 3D-model has been produced by CATIA software. To analyze the system mobility, a virtual model was developed with ADAMS Software. This simulation included different mobility maneuvers such as stair climbing, gap crossing and travelling over steep slopes. The simulations enabled us to define motor torque requirements. We performed many experiments with manufactured prototype under various terrain conditions Such as stair climbing, gap crossing and slope elevation. In experiments, HIRAD shows good overcoming ability for the tested terrain conditions.

Trajectory planning and four-leg coordination for stair climbing in a quadruped robot

Abstract: We report on the algorithm of trajectory planning and four leg coordination for quasi-static stair climbing in a quadruped robot. The development is based on the geometrical interactions between the robot legs and the stair, starting from single-leg analysis, followed by two-leg collaboration, and then four-leg coordination. In addition, a brief study on stability of the robot is also reported. Finally, simulation and experimental test are also executed to evaluate the performance of the algorithm.

Novel design of a small field robot with multi-active crawlers capable of autonomous stair climbing

Abstract: Mobile robots often encounter complex obstacles during their operation, not the least of which are stairs. Suitable mechanical structures and adequate control algorithms are both equally important in stair climbing. This paper proposes a novel design for a multi-active crawler robot (MACbot) capable of autonomous stair climbing. The MACbot has four track modules for extended mobility and a recovery arm that facilitates self-rescue capabilities. By adopting the proposed smart clutch mechanism, the MACbot can provide a variety of motions with a minimum number of motors. This paper presents a static analysis for the mechanical design and details the stability analysis for an autonomous stair climbing algorithm. A series of experiments show that the MACbot can autonomously climb stairs reasonably well.

STARCLY robot — A novel compact stair climbing robot

Abstract: In this paper, we describes a new design of a robot that is suitable for climbing up and down stairs. This design combines the advantage of using tracks and the robotic arm linkages to achieve robust climbing under the real-world conditions. Simulation models were initially used to develop the climbing sequences and later applied on a real prototype. System architecture of the robot is presented. All experimental and refinement of the climbing sequences was carried out using the prototype and the final product is an autonomous robot that is able to climb the stairs successfully.

The research of tension optimal estimation and stair-climbing ability of transformationwheelchair robot

Abstract: To meet the rapid increasing demand of the equipment assisting the disabled and the old, a novel style transmuting track wheelchair robot is developed. It has the characteristic that the track tension can be determined dynamically. Compared to traditional method that keeps track tension constantly, dynamically determining tension can reduce power consumption obviously. Based on the fact that modeling track tension is complex, a fuzzy logic decision making method is developed to estimate the proportion of various factors that have effect on track tension. Combining with least square method, we get track tension optimal estimation algorithm. Considering the low speed characteristic of the wheelchair as climbing stairs and the track tension got by estimation algorithm, the paper develops a statics model of the wheelchair for the starting stage of stair-climbing. Simulation results prove that the wheelchair can climb stairs stably when it takes advantage of tension estimation algorithm.

Electric wheelchair capable of climbing stairs

Abstract: The utility model relates to an electric wheelchair capable of climbing stairs, which comprises a vehicle frame, a chair, an electric speed changer and a walking mechanism, wherein the walking mechanism is provided with driving wheels, driven wheels and a chain track, the driving wheels and the driven wheels are arranged under the vehicle frame, and climbing assistance devices are arranged on the vehicle frame. The utility model is structurally characterized in that a support frame is connected on wheel shafts of the driven wheels, a stair climbing back wheel and a stair climbing front wheel are arranged on the support frame, a stair climbing chain track is matched with the stair climbing front wheel and the stair climbing back wheel, a pulling shaft is arranged on one end of the support frame and is matched with a slotted hole formed on the bottom end of a pulling rod, the pulling rod is connected with a rotating shaft of the vehicle frame, the upper end of the pulling rod is connected with a pulling rod handle, a position clamping plate is matched with the pulling rod, the position clamping plate is fixed on the vehicle frame, the climbing assistance devices are divided into four groups which are respectively arranged on the wheel shafts of the driven wheels on the left side and the right side of the front part of the vehicle frame and arranged on the wheel shafts of the driving wheels on the left side and the right side of the back part of the vehicle frame, a connecting rod is connected between the left side and the right side, and the chair is hanged on the vehicle frame through a hanging shaft and a hanging frame. The utility model has the advantages that the wheelchair can go upstairs and downstairs, the integral structure is simple, the operation is easy, and the action is flexible and reliable.

Straight Walking and Stair Climbing Gait of Quadruped Robot Based on Static Balance

Abstract: To improve obstacle climbing performance of the quadruped robot, stability margin is selected as the criterion of quadruped static balance, and quadrant boundary formed by touchdown points is taken as the stride possibility criterion in various initial conditions. All gaits are classified into 24 types by stride sequences. Based on the evaluation guidelines including minimal locomotion space demand, maximal stability margin, and best body adjustment coordination, contrast analyses on all 24 basic gaits are performed. Furthermore, a projection method combined with planar statically balanced gait theory is proposed to solve stair climbing gait problem, and systematic simulation of stair climbing gait is implemented to meet the 3 evaluation guidelines mentioned above. The simulation results provide theoretical foundation for selecting quadruped walking and stair climbing gaits. Experiments testify the validity of this method.

Correlation of Subjective Questionnaires With Cardiac Function as Determined by Exercise Testing in a Pediatric Population

Abstract: Background: Although exercise testing is an important objective method used to assess cardiopulmonary function, subjective assessment often is used as a proxy in the clinical setting. This study aimed to determine whether responses to a subjective functional capacity questionnaire administered to parents and patients in a pediatric exercise laboratory correlate with objective assessment of functional capacity, measured by peak oxygen consumption during maximal voluntary exercise testing. Methods: Subjective questionnaire responses and exercise test results collected over 10 years were retrospectively analyzed. Symptoms and physical capabilities were assessed using a 6-point Likert scale regarding the ability to attend school/work, walk, climb stairs, and run, as well as the frequency of fatigue, palpitations, and chest pain. Values of 0 to 3 were considered abnormal, whereas values of 4–5 were regarded as normal. Exercise testing was performed on a stationary cycle ergometer with a continuous ramping protocol. Heart rate and oxygen saturation were continuously monitored. Blood pressures and electrocardiograms (ECGs) were obtained at 2-min intervals. Metabolic gas analysis was performed using a breath-by-breath method. The results of the exercise testing were normalized for body size and expressed as a percentage of predicted peak oxygen consumption (%pVO2). Results: Very weak but statistically significant correlations (τ < 0.25; P < 0.05) between the scores of the school/work, walking, stair climbing, running, and fatigue items and %pVO2 were found using Kendall’s rank correlations. Conclusions: The subjective Likert scales used to assess basic physical capacity and cardiac-associated symptoms have limited ability to predict actual functional capacity as measured by %pVO2 achieved. The very weak rank-order correlation between %pVO2 achieved and the subjective reporting of the ability to attend school/work, walk, climb stairs, and run has low clinical significance and will not be useful in predicting functional capacity within the clinic setting.

Dynamic analysis for stair-climbing of a new-style wheelchair robot

Abstract: In this paper, a wheelchair robot equipped with new-style variable-geometry-tracked mechanism is proposed. Different from general variable-geometry-tracked mechanisms, the key feature of this new-style mechanism is that it can adapt to convex terrain and transform to concave geometry by active control of track tension, based on which the ability of stair-climbing of traditional wheelchair is improved. For obtaining the dynamic characteristic of stair-climbing which is crucial to the robot design, the locomotion and transformation rule for the robot during different climbing phases is presented, the dynamic models of the robot whole body and its fundamental components are established. Finally the dynamic simulation for stair-climbing is performed, and the drive characteristic of the robot under different climbing conditions is obtained. The simulation results provide theoretical foundation to the future work of driving system design and mechanical parameters optimization.

Stair climbing smart wheel chair

Abstract: A stair climbing smart wheel chair belongs to the field of rehabilitation medical treatment projects, and the stair climbing smart wheel chair is produced through research and tests for nine years aiming at enabling people using wheel chairs to go upstairs and downstairs by themselves. The structure is that a pedrail is longitudinally installed in the position between two small wheels, a hydraulic system controls the pedrail, the pedrail is contacted with stairs when being used for going upstairs and downstairs, the chair seat is supported by three points of the pedrail and two big wheels when the wheel chair is used for going upstairs and downstairs, a motor is used to drive the pedrail and the big wheel to advance synchronously, connection: the small wheels are installed on the front portion, big wheels are installed on the rear portion through two symmetrical arc-shaped castings, two ends are transversely connected and fixed, a meshing orbit is arranged on a casting arc, two groups of bearings are arranged at the bottom of the chair, the chair is supported by the bearing and is placed on the arc, the motor is used to drive the gear to drive the chair to move along the arc to adjust the balance of the chair and to adjust the gravity center of the wheel chair, the wheel chair is provided with three direct current motors which are controlled by a single chip microcomputer, automatic stair climbing can be realized: automatic conversion function, automatic advancing, automatic balancing, automatic gravity center adjustment, automatic stopping advancing, and automatic reset of initial states, a stopping device is installed on the wheel chair, the wheel chair can be stopped on each chair, the wheel chair has reasonable and simple structure, easy operation and safe use, can automatic realizing going upstairs and downstairs, the pedrail can not generate damage on stairs made of any materials.