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Showing papers on "Stair climbing published in 2020"


Journal ArticleDOI
TL;DR: A novel stair-climbing wheelchair operated by human upper body using lever propelled rotary-legs with posture transition mechanism to enable extended functionality of the regular wheelchair without the need of heavy, expensive mechanisms or electric motors.
Abstract: This paper describes a novel stair-climbing wheelchair operated by human upper body using lever propelled rotary-legs with posture transition mechanism. The design principle of this wheelchair is t...

18 citations


Journal ArticleDOI
TL;DR: Preoperative hand-grip strength can be used in preoperative screening for stair ascent and descent ability after total knee arthroplasty (TKA), and there was a strong positive correlation between this strength and functional limitation after TKA.

15 citations


Journal ArticleDOI
TL;DR: Comparing the differences in kinematics and muscle activations during climbing on regular stairs and a stairmill would provide additional insights into the design of future rehabilitation systems and to interpret human data obtained from stairmills.

11 citations


Journal ArticleDOI
TL;DR: A gait algorithm based on a pace gait is proposed, and the performance of this proposed stair-climbing gait for a four-wheeled vehicle is evaluated.
Abstract: This paper proposes a stair-climbing gait for a four-wheeled vehicle. The idea and methodology of climbing stairs are described, and the results of experiments are shown. Crawler-type vehicles and vehicles with special, complicated mechanisms are commonly used for climbing continuous steps (stairs). In contrast, in this paper, a four-wheeled vehicle with additional degrees of freedom, whose mechanism is not as complicated, is discussed. A gait algorithm based on a pace gait is proposed, and its performance is evaluated.

10 citations


Journal ArticleDOI
TL;DR: Single, subjectively "light" intensity stair climbing and descending bouts as short as 1 min in duration attenuate the postprandial glucose response in normal weight individuals following consumption of a mixed meal.
Abstract: Background and Aims Postprandial blood glucose (PBG) is an independent predictor of disease and mortality risk. To date, the shortest, single, moderate intensity exercise intervention to reduce PBG is a 1-min bout of stair stepping during an oral glucose tolerance test. Whether this effect translates to real meal consumption is unknown. Methods and Results Subjects (N=30) participated in a randomized controlled crossover trial performing 0min (seated control), 1min, 3min or 10min of stair climbing and descending bouts (SCD) at a self-selected pace after consumption of a mixed meal on four separate visits. Compared to control, all SCD reduced PBG at least one timepoint: at 30-minutes the 3min (-10.8(-18.7 to -2.8)mg/dL, p = 0.010) and 10min (-36.3(-46.4 to -26.3)mg/dL), p Conclusions Single, subjectively “light” intensity stair climbing and descending bouts as short as 1 minute in duration attenuate the postprandial glucose response in normal weight individuals following consumption of a mixed meal. More pronounced effects require longer bouts in a dose-dependent manner.

10 citations


Journal ArticleDOI
TL;DR: The TENS intervention may be an option for reducing the burden of early-stage knee OA and post-hoc correlation analyses revealed a non-significant but positive relationship between the pain relief effect and improved 11-step SCT time in the TENS group but not in the sham-TENS group.
Abstract: This study aimed to examine the effect of transcutaneous electrical nerve stimulation (TENS) on stair climbing capacity in individuals with pre-radiographic to mild knee osteoarthritis (OA). This is a secondary analysis of data from a single, participant-blinded, randomized controlled trial with a pre-post design. Participants with pre-radiographic to mild knee OA (mean age, 59.1 years; 72.9% women) were randomly assigned into two groups, a TENS (n = 30) and a sham-TENS groups (n = 29). TENS or sham-TENS treatments were applied to all participants by using the prototype TENS device with pre-specified parameters. The primary outcome measures included valid and reliable functional measures for stair climbing (stair-climb test [SCT]), visual analog scale for knee pain during the SCT, and quadriceps muscle strength. TENS improved SCT time by 0.41 s (95% confidence interval [CI]: 0.07, 0.75). The time reduction in the transition phase explains the TENS therapeutic effect. Post-hoc correlation analyses revealed a non-significant but positive relationship between the pain relief effect and improved 11-step SCT time in the TENS group but not in the sham-TENS group. These results indicate that the TENS intervention may be an option for reducing the burden of early-stage knee OA.

9 citations


Journal ArticleDOI
TL;DR: A novel multi-robotsystem composed of tracked mobile robots used for collaborative transportation and investigates the stairs climbing process, which is validated by the stair climbing experiments.

9 citations


Proceedings ArticleDOI
01 Nov 2020
TL;DR: Results from an able-bodied human subject experiment demonstrate that the exoskeleton is able to reduce muscular activation of the primary muscles related to the knee and ankle joints during sit-to-stand, stand- to-sit, level walking, and stair climbing.
Abstract: This paper presents the design and implementation of a novel multi-activity control strategy for a backdrivable knee-ankle exoskeleton. Traditionally, exoskeletons have used trajectory-based control of highly geared actuators for complete motion assistance. In contrast, we develop a potential energy shaping controller with ground reaction force (GRF) feedback that facilitates multi-activity assistance from a backdrivable exoskeleton without prescribing pre-defined kinematics. Although potential energy shaping was previously implemented in an exoskeleton to reduce the user’s perceived gravity, this model-based approach assumes the stance leg is fully loaded with the weight of the user, resulting in excessive control torques as weight transfers to the contralateral leg during double support. The presented approach uses GRF feedback to taper the torque control output for any activity involving multiple supports, leading to a closer match with normative joint moments in simulations based on pre-recorded human data during level walking. To implement this strategy, we present a custom foot force sensor that provides GRF feedback to the previously designed exoskeleton. Finally, results from an able-bodied human subject experiment demonstrate that the exoskeleton is able to reduce muscular activation of the primary muscles related to the knee and ankle joints during sit-to-stand, stand-to-sit, level walking, and stair climbing.

8 citations


Journal ArticleDOI
TL;DR: Small immediate changes in kinematics and angular impulses - primarily at the ankle - were observed when foot orthoses were worn during walking or stair ambulation in individuals with persistent PFP.

8 citations


Journal ArticleDOI
TL;DR: This study quantified improvement of gait and stair climbing immediately after a genicular nerve blockade in patients suffering from knee OA in Cameroon, the first study objectifying this effect, through wearable sensors.
Abstract: Genicular nerve blockade is a possible treatment for patients with knee osteoarthritis. Pain relief and improvement in functioning is expected. This procedure could be of major interest for patients in low-income countries where total knee arthroplasty is not available for the population. This study aims at assessing the immediate benefits on pain, gait, and stairs kinematics after a genicular nerve blockade in patients suffering from knee osteoarthritis in Cameroun. A prospective study was carried out on 26 subjects in Cameroun. A genicular nerve blockade was performed on 14 women with painful knee osteoarthritis grade 2–4. Lower limb joint angles were recorded with inertial sensors before and 1 h after injection. Patient-reported outcomes of pain and perceived difficulty were collected, as well as 10 m and 6 min walking tests. A reliability analysis of inertial sensors was performed on a sample of 12 healthy subjects by calculating the intraclass correlation coefficient and the standard error of measurement. Pain and perceived difficulty decreased significantly (p < 0.001). Cadence increased significantly in stairs climbing (upstairs: + 7.7 steps/min; downstairs: + 7.6 steps/min). There was an improvement for hip sagittal range of motion during gait (+ 9.3°) and pelvis transverse range of motion in walking upstairs (− 3.3°). Angular speed range of the knee in the sagittal plane and of the hip in the frontal plane increased significantly in stairs descent (+ 53.7°/s, + 94.5°/s). This study quantified improvement of gait and stair climbing immediately after a genicular nerve blockade in patients suffering from knee OA in Cameroon. This is the first study objectifying this effect, through wearable sensors. Pan African Clinical Trial Registry, PACTR202004822698484 . Registered 28 March 2020 - Retrospectively registered.

7 citations


Journal ArticleDOI
TL;DR: A novel method using the 2 parameters of yaw-angle error and lateral position error is proposed and it is indicated that the proposed design changes may be declared an improvement of the robot.
Abstract: This paper describes about improvements in the mobility of a stair climbable mobile robot on a step-field. A step-field, standardized by the National Institute of Standards and Technology (NIST), is a simulated artificial rough terrain used for testing rescue robots. Its use was popularized worldwide in the RoboCup Rescue contest, but a method for evaluating test results from it has yet to be established sufficiently. The author of this paper attempts to evaluate the mobility of stair climbable mobile robots on step-fields. A novel method using the 2 parameters of yaw-angle error and lateral position error is proposed. Two actual robots, SMART-IV type A and SMART-IV type B, are constructed and evaluated on small step-fields. The test results indicate that both robots can traverse the step-field under some appropriate conditions, but a comparison of the results indicates that the proposed design changes may be declared an improvement of the robot.

Journal ArticleDOI
TL;DR: Pain catastrophizing in knee OA patients showed significantly decreased stair climbing ability and ability to stand from a seated position and walk were not affected by pain catastrophize.
Abstract: The association between pain catastrophizing and ability to perform activities of daily living (ADL) requiring weight bearing, in particular stair climbing, standing from a seated position, and walking, in individuals with knee osteoarthritis (OA) is unclear. This study aimed to investigate the association between pain catastrophizing and ability to perform these ADLs by this population. This cross-sectional study included individuals with knee OA (Kellgren and Lawrence grades 1–4). The ability to perform ADL was evaluated using the knee OA-related health domain measure (Japanese Knee Osteoarthritis Measure). Pain catastrophizing was evaluated using the Pain Catastrophizing Scale. The association between pain catastrophizing and ability to perform ADL, in particular stair climbing, standing from a seated position, and walking, was evaluated using the logistic regression analysis. Three types of sensitivity analysis were performed to validate the results of the logistic regression analysis. A total of 151 participants were included in the final analysis. When adjusted for covariates, those with pain catastrophizing showed significantly decreased stair climbing ability (odds ratio 8.84; 95% confidence interval 1.37 to 56.92). Moreover, the results did not change even with sensitivity analysis. By contrast, when adjusted for covariates, those with pain catastrophizing did not show significantly decreased ability to stand from a seated position and walk. Pain catastrophizing in knee OA patients showed significantly decreased stair climbing ability. There is a need to consider the effect of pain catastrophizing in rehabilitation of knee OA patients with decreased ability to climb stairs.

Journal ArticleDOI
TL;DR: Men were faster than women in this specific running discipline; however, women were able to outperform men in very specific situations (i.e., specific age groups and specific numbers of stairs).
Abstract: Though there are exhaustive data about participation, performance trends, and sex differences in performance in different running disciplines and races, no study has analyzed these trends in stair climbing and tower running. The aim of the present study was therefore to investigate these trends in tower running. The data, consisting of 28,203 observations from 24,007 climbers between 2014 and 2019, were analyzed. The effects of sex and age, together with the tower characteristics (i.e., stairs and floors), were examined through a multivariable statistical model with random effects on intercept, at climber's level, accounting for repeated measurements. Men were faster than women in each age group (p 69 years), and the difference in performance stayed around 0.20 km/h, with a minimum of 0.17 at the oldest age. However, women were able to outperform men in specific situations: (i) in smaller buildings ( 69 years; (ii) in higher buildings (>2200 stairs), for age groups 69 years. In summary, men were faster than women in this specific running discipline; however, women were able to outperform men in very specific situations (i.e., specific age groups and specific numbers of stairs).

Journal ArticleDOI
TL;DR: The developed system is a new type of robotic gait training system that could induce phasic lower limb muscle activation patterns, and its clinical efficacy will be validated in clinical trials after regulatory approval.
Abstract: This paper introduces a newly developed robotic gait training system for lower-limb rehabilitation of stroke patients. The system (Cyborg-Trainer L; Cyborg-Lab Co., Korea) provides a stair-climbing mode in addition to the conventional level-walking mode by leveraging a unique exoskeleton structure with separately operable foot plates. Unlike conventional end-effector type gait training robots, the subject’s feet are not constrained by foot plates, but are free to emulate the ground or a set of stairs. The ground reaction force is measured by force sensors in the foot plates and utilized to compensate for the vertical movement of pelvis. The exoskeleton structures are connected at hip, knee, and ankle joints, and these can support a patient’s weight to ensure a normal gait pattern. The system has four control modes with different levels of assistive or resistance force. To show the feasibility of the developed training mode, a series of experiments measuring muscle activity were conducted during 1) level-walking with the robot, 2) level-walking on a treadmill without a robot, 3) stair-climbing with the robot, and 4) actual stairclimbing without a robot. The muscle activation from the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius medialis of the dominant leg of five healthy adults were measured and analyzed. Results showed that all muscles had a rhythmic muscle activation pattern. Even though muscle activation patterns were different between gaits using the robotic gait system and those not using it, reduced amplitudes and phasic muscle activations were observed during the training in the robotic system. The developed system is a new type of robotic gait training system that could induce phasic lower limb muscle activation patterns, and its clinical efficacy will be validated in clinical trials after regulatory approval.

Journal ArticleDOI
TL;DR: A control method to restrain the movement of the wheels when the stair climbing speed is increased is proposed considering the dynamic equilibrium of the pitch angle and confirmed the effect of the restraining wheels’ movement when the proposed method was applied.
Abstract: The wheelchair is the major means of transport for elderly and physically disabled people in their daily lives. However it cannot overcome architectural barriers such as curbs and stairs. In this study, we developed an inverted-pendulum-type robotic wheelchair for climbing stairs. This wheelchair has a seat slider and two rotary links between the front and rear wheels on each side. When climbing stairs, the wheelchair rotates the rotary links while maintaining an inverted state of a mobile body by controlling the position of the center of gravity using a seat slider. In previous research, we confirmed that the wheelchair can climb by applying the control method consisting of a center-of-gravity control phase and rotary link control phase. However, it took approximately 15 s to rotate the rotary links during climbing because faster climbing causes the movement of wheels and the wheelchair to fall. This paper focuses on a control method to restrain the movement of the wheels when the stair climbing speed is increased. We realized that the movement was caused by forces acting on the pitch angle, such as the inertial force and the reaction of the driving force. We proposed the method considering the dynamic equilibrium of the pitch angle and confirmed the effect of the restraining wheels’ movement when the proposed method was applied.

Proceedings ArticleDOI
01 Aug 2020
TL;DR: A study to evaluate the effects of sloshing phenomena while a humanoid robot climbs stairs while carrying water containers using the full-sized humanoid DRC-Hubo as an experimental platform and an algorithm which allows the robot to walk while carryingWater buckets.
Abstract: This paper presents a study to evaluate the effects of sloshing phenomena while a humanoid robot climbs stairs while carrying water containers. Currently humanoid robots can perform a wide range of tasks including handling tools, climbing ladders, and patrolling rough terrain. However, when it comes to manipulation of objects humanoids are fairly limited. This becomes more apparent when humanoids have to handle non-rigid objects. Although many full-sized humanoids cost an extensive amount of money, they fail to respond to common tasks during disaster relief such as delivering water to the victims or possible fires. After disasters such as Hurricane Maria, the need for humanoid robots to assist in these scenarios is becoming increasingly evident. In previous work the authors have developed an algorithm which allows the robot to walk while carrying water buckets. Experiments conducted use the full-sized humanoid DRC-Hubo as an experimental platform. Moreover, a sloshing reduction controller is implemented in order to suppress rocking disturbances. The system was integrated via ROS (Robot Operating System). Additionally, the sloshing reduction was evaluated based on sensor data evaluation.

Journal ArticleDOI
01 Mar 2020
TL;DR: Using Matlab simulation, the simulation results show that in the physical training robot speed control system, the fuzzy PID control is more stable than the traditional PID control start and braking process, with higher comfort, smaller error and higher precision.
Abstract: Physical exercise assisted robot speed regulation has higher requirements on dynamic characteristics of the system and faster response speed, and there are many uncertain factors in the process of climbing athletes in the process of climbing the building. Single closed-loop negative feedback control based on traditional control strategy System speed regulation is unsatisfactory. Based on the above problems, this paper establishes the mathematical model of the fuzzy PID control system of the physical exercise assisted robot speed control system, and designs a double closed loop speed control system based on fuzzy PID, and compares it with the traditional PID control; The sprint speed is given to the sinusoidal speed given curve by referring to the stability of the elevator climbing process and the comfort of the occupant. Using Matlab simulation, the simulation results show that in the physical training robot speed control system, the fuzzy PID control is more stable than the traditional PID control start and braking process, with higher comfort, smaller error and higher precision. Stair climbing has a strong use value and brings good value to the economy and society.

Journal ArticleDOI
24 Jan 2020-PLOS ONE
TL;DR: The overweight, those carrying a large bag and females avoided both stair climbing and descent more frequently than their comparison groups, and greater avoidance of stairs in these demographic subgroups when the alternative means of ascent was a sloped ramp.
Abstract: Background Locomotion is an energy costly behaviour, particularly when it entails raising weight against gravity. Minimization of locomotor costs appears a universal default. Avoidance of stair climbing helps humans minimise their energetic costs. In public access settings, demographic subgroups that raise more ‘dead’ weight than their comparison groups when climbing are more likely to avoid stairs by choosing the escalator. Individuals who minimise stair costs at work, however, can accumulate a deficit in energy expenditure in daily life with potential implications for weight gain. This paper tests the generality of avoidance of stairs in pedestrians encumbered by additional weight in three studies. Methods Pedestrian choices for stairs or the alternative were audited by trained observers who coded weight status, presence of large bags and sex for each pedestrian. Sex-specific silhouettes for BMIs of 25 facilitated coding of weight status. Choices between stairs and a lift to ascend and descend were coded in seven buildings (n = 26,981) and at an outdoor city centre site with the same alternatives (n = 7,433). A further study audited choices to ascend when the alternative to stairs was a sloped ramp in two locations (n = 16,297). Analyses employed bootstrapped logistic regression (1000 samples). Results At work and the city centre site, the overweight, those carrying a large bag and females avoided both stair climbing and descent more frequently than their comparison groups. The final study revealed greater avoidance of stairs in these demographic subgroups when the alternative means of ascent was a sloped ramp. Discussion Minimization of the physiological costs of transport-related walking biases behaviour towards avoidance of stair usage when an alternative is available. Weight carried is an encumbrance that can deter stair usage during daily life. This minimization of physical activity costs runs counter to public health initiatives to increase activity to improve population health.

Journal ArticleDOI
TL;DR: The stability analysis shows that the control method can achieve a stable stair-climbing motion and the result indicates that the robot can climb the stairs, and the required time for climbing a single step is approximately 1.8 s.
Abstract: In this study, the control of a two-wheeled stair-climbing inverted pendulum robot and its climbing motion are analyzed and discussed. The robot adopts a state-feedback controller with a feed-forwa...

Journal ArticleDOI
TL;DR: This paper presents a prototype of an above-knee prosthetic leg with active knee and ankle joints while using the proposed robust control law.
Abstract: The locomotion of people with amputation is slower, less stable and requires more metabolic energy than the locomotion of physically fit individuals. Individuals with amputation of the lower extremities fall more often than able individuals and often have difficulty moving on uneven terrain and stairs. These challenges can mostly be attributed to the use of passive mechanical prosthetic legs that do not react actively to perturbations. Latest submitted solutions for active prosthetic devices of the lower extremities can significantly improve mobility and quality of life for millions of people with lower limb amputation, but challenges in control mechanisms of such devices are currently limiting their clinical viability. In this paper we present a prototype of an above-knee prosthetic leg with active knee and ankle joints while using the proposed robust control law.

Journal ArticleDOI
01 Dec 2020
TL;DR: An alternative movement identification technique for the analysis of the ingress movement that may be used to clinically assess knee bearings and aid in movement simulations and vehicle design is described.
Abstract: Background: Post-operative performance of knee bearings is typically assessed in activities of daily living by means of motion capture. Biomechanical studies predominantly explore common tasks such as walking, standing and stair climbing, while overlooking equally demanding activities such as embarking a vehicle. Aims: The aim of this work is to evaluate changes in the movement habits of patients after total knee arthroplasty surgery in comparison to healthy age-matched control participants. Methods: A mock-up car was fabricated based on the architecture of a common vehicle. Ten control participants and 10 patients with severe osteoarthritis of the knee attended a single- and three-motion capture session(s), respectively. Participants were asked to enter the car and sit comfortably adopting a driving position. Three trials per session were used for the identification of movement strategies by means of hierarchical clustering. Task completion time was also measured. Results: Patients' movement behaviour didn't change significantly following total knee arthroplasty surgery. Control participants favoured different movement strategies compared to patients post-operatively. Group membership, height and sidedness of the affected joint were found to be non-significant in task completion time. Conclusion: This study describes an alternative movement identification technique for the analysis of the ingress movement that may be used to clinically assess knee bearings and aid in movement simulations and vehicle design.

Proceedings ArticleDOI
13 Oct 2020
TL;DR: This paper aims to analyze the range of motions and characteristics of a quadruped robot for stair climbing and crossing over an obstacle with significant aspects of leg dimensions and joint ranges with geometrical analysis to find the optimal position of the feet.
Abstract: This paper aims to analyze the range of motions and characteristics of a quadruped robot for stair climbing and crossing over an obstacle. Humans have a higher range than quadruped animals due to longer legs. We can make fewer steps and reach the same distance, can climb stairs by two or three steps and not only one, and cross over high obstacles thanks to our leg range. However, stability is different because quadruped has four contact points, whereas humans have only. Quadrupeds maintain walking stability because their gravity center falls within the triangle of support from the three legs when one is up, but in the same condition, humans encounter a complex challenge to maintain equilibrium. We propose using these inherent characteristics of a quadruped robot for motion analysis of stair climbing by two or three steps and cross over a big obstacle while maintaining high stability in a quadruped robot. We aboard in the discussion significant aspects of leg dimensions and joint ranges with geometrical analysis to find the optimal position of the feet. The motion effectiveness was verified experimentally by implementing the motions from the preliminary tests to a quadruped robot.

Journal ArticleDOI
TL;DR: A minimal complexity algorithm composed of a hierarchical classifier and a linear model to estimate the number of stair steps performed during everyday activities to help monitor the functional ability of the elderly.
Abstract: Wearable sensors play a significant role for monitoring the functional ability of the elderly and in general, promoting active ageing. One of the relevant variables to be tracked is the number of stair steps (single stair steps) performed daily, which is more challenging than counting flight of stairs and detecting stair climbing. In this study, we proposed a minimal complexity algorithm composed of a hierarchical classifier and a linear model to estimate the number of stair steps performed during everyday activities. The algorithm was calibrated on accelerometer and barometer recordings measured using a sensor platform worn at the wrist from 20 healthy subjects. It was then tested on 10 older people, specifically enrolled for the study. The algorithm was then compared with other three state-of-the-art methods, which used the accelerometer, the barometer or both. The experiments showed the good performance of our algorithm (stair step counting error: 13.8%), comparable with the best state-of-the-art (p > 0.05), but using a lower computational load and model complexity. Finally, the algorithm was successfully implemented in a low-power smartwatch prototype with a memory footprint of about 4 kB.

Journal ArticleDOI
TL;DR: Self-efficacy and biomechanics related to stair navigation in older adults are examined and positively primed older adults can navigate stairs with more confidence, quickness, and efficiency.
Abstract: Negative age-stereotypes can have widespread effects on older adult functionality; however, no research has explored psychophysical aspects of stair navigation after exposure to stereotype priming....

Journal ArticleDOI
TL;DR: Investigating the effects of motivational signage on stair usage in a predominantly Hispanic serving institution found it can effectively encourage more stair usage, and hence promote healthy behavior in a majority Hispanic-serving institution.
Abstract: Objective: Stair climbing is considered a good physical activity. Motivational signage has been successful in promoting stair usage in various settings. This study was to investigate the ef...

Journal ArticleDOI
11 Aug 2020
TL;DR: An autonomous spiral stair climbing method for tracked vehicles using the reaction force from side walls has been proposed and the applicable limitations of this method using a geometrical model are clarified.
Abstract: In this letter, an autonomous spiral stair climbing method for tracked vehicles using the reaction force from side walls has been proposed. Spiral stairs are one of the most difficult terrains for tracked vehicles because of their asymmetrical ground shape and small turning radius. Tracked vehicles are expected to be used in industrial plant inspection tasks, where robots should navigate on multiple floors by ascending the stairs. Spiral or curved stairs are installed as part of inspection passages for cylindrical facilities, such as boilers, chimneys, or large tanks. Previously, the authors have experimentally demonstrated that the wall-following motion is effective for stabilizing and accelerating spiral stair climbing. However, the complete automation of climbing motion or the analysis of why the same motion is generated even if a disturbance exists in the initial entry angle to the wall should be investigated. In this study, the authors developed an autonomous spiral stair climbing method using the wall reaction force and clarified the applicable limitations of this method using a geometrical model. Autonomous spiral stair climbing is realized by attaching passive wheels on its collision point and automating the motions of main tracks and sub-tracks. The geometrical model shows the expected trajectory of the robot on the spiral stairs, which suggests that the robot' s rotation radius converges to a specific value; this is experimentally confirmed by measuring the robot's motion. The wall-following motion of robots is equivalent to human inspectors grasping handrails while climbing stairs. Through collisions with surrounding objects, motion is stabilized and certainty is guaranteed.

Journal ArticleDOI
TL;DR: Findings indicate that there are small to large differences in medial-lateral postural control in the ACLR leg compared to the non-ACLR leg during stair descent.

Proceedings ArticleDOI
Yue Feng1, Huiming Wang1, Jing Wu1, Hanyu Song1, I-Ming Chen1 
18 Oct 2020
TL;DR: A novel self-balancing platform is designed for the stable stair climbing of AGV and the workspace not only allows the mechanism to reduce the vibration acting on the carried goods when the AGV is driving on uneven terrain but also allows the platform to maintain the center of gravity while theAGV is climbing.
Abstract: Task space beyond 2D planes brings challenges to the traditional automated guided vehicle (AGV) on goods delivery. In this paper, a novel self-balancing platform is designed for the stable stair climbing of AGV. While the AGV is moving in a constructional site, this mechanism enhances the AGV to handle heavy payload or even carry another operating robot, through keeping them horizontal to the ground over time. In the design, the two degree-of-freedom (DOF) of this mechanism allows the platform to rotate around two mutually perpendicular axes. The rotation ranges are [−15°, 15°] and [0°, 40°], respectively. Through the feedback of an inertial measurement unit (IMU), the self-balancing control can be achieved. The demonstration show that the workspace not only allows the mechanism to reduce the vibration acting on the carried goods when the AGV is driving on uneven terrain but also allows the platform to maintain the center of gravity (CG) while the AGV is climbing.

Journal ArticleDOI
TL;DR: Assessing the accuracy of step-counting with different smartphones using the S Health step counting application at long and short walking distances, and stair climbing suggests that accuracy of smart-phones increase with increased number of steps and correspond to newer model.
Abstract: Background: ‪The S Health application provides an estimate of the amount of physical activity by measuring the number of steps during activities. The purpose was to assess the accuracy of step-counting with different smartphones using the S Health step counting application at long and short walking distances, and stair climbing. Material and methods: ‪26 participants (aged 28.85 ± 4.85 years) conducted three tests: 20-step test, 60-step stair test, and 6-minute walk test. Three smartphone models of the latest generation and two models of an earlier one were assessed. The StepWatch pedometer was used as a criterion. Results: Only one phone of the latest generation produced the most consistent and accurate results as compared to the pedometer in the 60-step stair test and 6-minute walk test (r=0.840), while the correlation of the other four smartphones was weak, from r=0.257 to r=0.482. Generally, the accuracy increased with the increasing amount of steps in all devices and the mean absolute percentage error decreased. Errors ranged between 5.8 and 56.9% for the 20-step test, 1.9-22.4% for the 60-step stair test, and 1.1-17.8% for the 6-minute walk test. Conclusions: The results suggest that accuracy of smart-phones increase with increased number of steps and correspond to newer model.

Journal ArticleDOI
TL;DR: To improve the climbing function of patients with THA, it is important to not only focus on the recovery of muscle strength in the hip extensors but also improve muscle strength at heel strike normalized by body weight.