Background:One-legged pedaling is of interest to elite cyclists and clinicians.However,muscular usage in 1-legged vs.2-legged pedaling is not fully understood.Thus,the study was aimed to examine changes in leg muscle ...Background:One-legged pedaling is of interest to elite cyclists and clinicians.However,muscular usage in 1-legged vs.2-legged pedaling is not fully understood.Thus,the study was aimed to examine changes in leg muscle activation patterns between 2-legged and 1-legged pedaling.Methods:Fifteen healthy young recreational cyclists performed both 1-legged and 2-legged pedaling trials at about 30 Watt per leg.Surface electromyography electrodes were placed on 10 major muscles of the left leg.Linear envelope electromyography data were integrated to quantify muscle activities for each crank cycle quadrant to evaluate muscle activation changes.Results:Overall,the prescribed constant power requirements led to reduced downstroke crank torque and extension-related muscle activities(vastus lateralis,vastus medialis,and soleus)in 1-legged pedaling.Flexion-related muscle activities(biceps femoris long head,semitendinosus,lateral gastrocnemius,medial gastrocnemius,tensor fasciae latae,and tibialis anterior)in the upstroke phase increased to compensate for the absence of contralateral leg crank torque.During the upstroke,simultaneous increases were seen in the hamstrings and uni-articular knee extensors,and in the ankle plantarflexors and dorsiflexors.At the top of the crank cycle,greater hip flexor activity stabilized the pelvis.Conclusion:The observed changes in muscle activities are due to a variety of changes in mechanical aspects of the pedaling motion when pedaling with only 1 leg,including altered crank torque patterns without the contralateral leg,reduced pelvis stability,and increased knee and ankle stiffness during the upstroke.展开更多
Recent developments have demonstrated that the brake pedal simulator(BPS)is becoming an indispensable apparatus for the break-by-wire systems in future electric vehicles.Its main function is to provide the driver with...Recent developments have demonstrated that the brake pedal simulator(BPS)is becoming an indispensable apparatus for the break-by-wire systems in future electric vehicles.Its main function is to provide the driver with a comfortable pedal feel to improve braking safety and comfort.This paper presents the development and control of an adjustable BPS,using a disk-type magnetorheological(MR)damper as the passive braking reaction generator to simulate the traditional pedal feel.A detailed description of the mechanical design of the MR damper-based BSP(MRDBBPS)is presented in this paper.Several basic performance experiments on the MRDBBPS prototype are conducted.A returnto-zero(RTZ)algorithm is proposed to avoid hysteresis and improve the repeatability of the pedal force.In addition,an RTZ algorithm-based real-time current-tracking controller(RTZRC)is designed in consideration of the response lag of the coil circuit.Finally,an experimental system is established by integrating the MRDBBPS prototype into a selfdeveloped automotive MR braking test bench(AMRBTB),and several control and braking experiments are performed.This research proposes a RTZRC control algorithm which can significantly increase the tracking accuracy of the brake pedal characteristic curve,particularly at a high pedal velocity.Additionally,the designed MRDBBPS prototype can achieve an effective and favorable control of the AMRBTB with a good repeatability.展开更多
Reducing energy consumption has become a matter of increasing concern for electric vehicle owners. EcoDriver is a project funded by the European Commission, searching for new eco-driving solutions for reducing energy ...Reducing energy consumption has become a matter of increasing concern for electric vehicle owners. EcoDriver is a project funded by the European Commission, searching for new eco-driving solutions for reducing energy consumption in private and public transport. EcoDriver’s main purpose is to teach efficient driving strategies and facilitate drivers’ decision-making processes through several feedback modalities, in order to help increase driving efficiency and therefore reduce energy consumption. In the present study, the Full ecoDriver System combined with a haptic feedback gas pedal was tested in real driving conditions to give answers to some questions about its effectiveness, efficiency, workload and acceptability in an electric vehicle. The sample profile was composed by thirty young but experienced drivers. They had to drive around an open road track which allowed several possible scenarios such as curves, intersection or roundabout, speed limit changes and preceding vehicles. Average speed was registered on each lap, likewise other subjective measurements. The main results suggest that the efficiency benefits achieved while driving depend on the event type and the feedback modality provided. For instance haptic feedback seems to be especially indicated for roundabouts. In addition, the visual feedback provided by the FeDS nomadic device helps to save energy and learn eco-driving strategies. These outcomes indicate how several feedback modalities could facilitate the decision making process, changing driving behaviour, reducing energy consumption and increasing safety. These questions would help advance further research on eco-driving Intelligent Transport Systems and driving behaviour issues.展开更多
In this paper,we present inequalities for volumes of subsimplices of a simplex and its pedal simplex and generalize them to m ＋ 1 simplices and their pedal simplices.
Once I found a pink moth on our front porch. I was per-haps eight years old, and it happened as I stepped out throughmy front door into the glass-enclosed vestibule, nearly like agreenhouse, where we left our boots in...Once I found a pink moth on our front porch. I was per-haps eight years old, and it happened as I stepped out throughmy front door into the glass-enclosed vestibule, nearly like agreenhouse, where we left our boots in the winter. A mothwas desperately trying to find its way off the porch. Several times I had found a bee or a moth trapped on展开更多
The tricks of many senior people who always keep themselves in good health is to massage their feet. There are many important acupuncture points on the soles of the feet, and the most important is located in the pit o...The tricks of many senior people who always keep themselves in good health is to massage their feet. There are many important acupuncture points on the soles of the feet, and the most important is located in the pit of the sole and is called Yong Quan Point, on the longevity point. Massaging this point frequently is good for improving the vitality of the body and replenishing展开更多
Yuan Jianglei has an amazing story to tell. The 27 year old is one of a handful of people who can say they have cycled through Africa - solo.Yuan began his epic adventure in the West African country of Benin, ending 1...Yuan Jianglei has an amazing story to tell. The 27 year old is one of a handful of people who can say they have cycled through Africa - solo.Yuan began his epic adventure in the West African country of Benin, ending 10,544 km and 333 days later in his hometown of Ningbo, east China＇s Zhejiang Province.展开更多
This paper presents the design and manufacture process of a wheel-less,modular snake robot with series elastic actuators to reliably measure motor torque signal and investigate the effectiveness of active stiffness co...This paper presents the design and manufacture process of a wheel-less,modular snake robot with series elastic actuators to reliably measure motor torque signal and investigate the effectiveness of active stiffness control for achieving adaptive snake-like locomotion.A polyurethane based elastic element to be attached between the motor and the links at each joint was designed and manufactured using water jet cutter,which makes the final design easier to develop and more cost-effective,compared to existing snake robots with torque measurement capabilities.The reliability of such torque measurement mechanism was examined using simulated dynamical model of pedal wave motion,which proves the efficacy of the design.A distributed control system was also designed,which with the help of an admittance controller,enables active control of the joint stiffness to achieve adaptive snake robot pedal wave locomotion to climb over obstacles,which unlike existing methods does not require prior information about the location of the obstacle.The effectiveness of the proposed controller in comparison to open-loop control strategy was verified by the number of experiments.The results show the capability of the robot to successfully climb over obstacles with the height of more than 55%of the diameter of the snake robot modules.展开更多
基金supported by the University of Massachusetts Amherst(SP:Graduate School Fellowship,and School of Public Health and Health Sciences Dean’s PhD Summer FellowshipGEC:Faculty Research Grant).
文摘Background:One-legged pedaling is of interest to elite cyclists and clinicians.However,muscular usage in 1-legged vs.2-legged pedaling is not fully understood.Thus,the study was aimed to examine changes in leg muscle activation patterns between 2-legged and 1-legged pedaling.Methods:Fifteen healthy young recreational cyclists performed both 1-legged and 2-legged pedaling trials at about 30 Watt per leg.Surface electromyography electrodes were placed on 10 major muscles of the left leg.Linear envelope electromyography data were integrated to quantify muscle activities for each crank cycle quadrant to evaluate muscle activation changes.Results:Overall,the prescribed constant power requirements led to reduced downstroke crank torque and extension-related muscle activities(vastus lateralis,vastus medialis,and soleus)in 1-legged pedaling.Flexion-related muscle activities(biceps femoris long head,semitendinosus,lateral gastrocnemius,medial gastrocnemius,tensor fasciae latae,and tibialis anterior)in the upstroke phase increased to compensate for the absence of contralateral leg crank torque.During the upstroke,simultaneous increases were seen in the hamstrings and uni-articular knee extensors,and in the ankle plantarflexors and dorsiflexors.At the top of the crank cycle,greater hip flexor activity stabilized the pelvis.Conclusion:The observed changes in muscle activities are due to a variety of changes in mechanical aspects of the pedaling motion when pedaling with only 1 leg,including altered crank torque patterns without the contralateral leg,reduced pelvis stability,and increased knee and ankle stiffness during the upstroke.
基金National Natural Science Foundation of China(Grant Nos.52175047 and 51505114)Anhui Provincial Natural Science Foundation of China(Grant No.2008085ME140).
文摘Recent developments have demonstrated that the brake pedal simulator(BPS)is becoming an indispensable apparatus for the break-by-wire systems in future electric vehicles.Its main function is to provide the driver with a comfortable pedal feel to improve braking safety and comfort.This paper presents the development and control of an adjustable BPS,using a disk-type magnetorheological(MR)damper as the passive braking reaction generator to simulate the traditional pedal feel.A detailed description of the mechanical design of the MR damper-based BSP(MRDBBPS)is presented in this paper.Several basic performance experiments on the MRDBBPS prototype are conducted.A returnto-zero(RTZ)algorithm is proposed to avoid hysteresis and improve the repeatability of the pedal force.In addition,an RTZ algorithm-based real-time current-tracking controller(RTZRC)is designed in consideration of the response lag of the coil circuit.Finally,an experimental system is established by integrating the MRDBBPS prototype into a selfdeveloped automotive MR braking test bench(AMRBTB),and several control and braking experiments are performed.This research proposes a RTZRC control algorithm which can significantly increase the tracking accuracy of the brake pedal characteristic curve,particularly at a high pedal velocity.Additionally,the designed MRDBBPS prototype can achieve an effective and favorable control of the AMRBTB with a good repeatability.
文摘Reducing energy consumption has become a matter of increasing concern for electric vehicle owners. EcoDriver is a project funded by the European Commission, searching for new eco-driving solutions for reducing energy consumption in private and public transport. EcoDriver’s main purpose is to teach efficient driving strategies and facilitate drivers’ decision-making processes through several feedback modalities, in order to help increase driving efficiency and therefore reduce energy consumption. In the present study, the Full ecoDriver System combined with a haptic feedback gas pedal was tested in real driving conditions to give answers to some questions about its effectiveness, efficiency, workload and acceptability in an electric vehicle. The sample profile was composed by thirty young but experienced drivers. They had to drive around an open road track which allowed several possible scenarios such as curves, intersection or roundabout, speed limit changes and preceding vehicles. Average speed was registered on each lap, likewise other subjective measurements. The main results suggest that the efficiency benefits achieved while driving depend on the event type and the feedback modality provided. For instance haptic feedback seems to be especially indicated for roundabouts. In addition, the visual feedback provided by the FeDS nomadic device helps to save energy and learn eco-driving strategies. These outcomes indicate how several feedback modalities could facilitate the decision making process, changing driving behaviour, reducing energy consumption and increasing safety. These questions would help advance further research on eco-driving Intelligent Transport Systems and driving behaviour issues.
基金Project supported by the National Natural Science Foundation of China (Grant No.10671117)the Foundation of the Education Department of Gansu Province (Grant No.0709-03)
文摘In this paper,we present inequalities for volumes of subsimplices of a simplex and its pedal simplex and generalize them to m ＋ 1 simplices and their pedal simplices.
文摘Once I found a pink moth on our front porch. I was per-haps eight years old, and it happened as I stepped out throughmy front door into the glass-enclosed vestibule, nearly like agreenhouse, where we left our boots in the winter. A mothwas desperately trying to find its way off the porch. Several times I had found a bee or a moth trapped on
文摘The tricks of many senior people who always keep themselves in good health is to massage their feet. There are many important acupuncture points on the soles of the feet, and the most important is located in the pit of the sole and is called Yong Quan Point, on the longevity point. Massaging this point frequently is good for improving the vitality of the body and replenishing
文摘Yuan Jianglei has an amazing story to tell. The 27 year old is one of a handful of people who can say they have cycled through Africa - solo.Yuan began his epic adventure in the West African country of Benin, ending 10,544 km and 333 days later in his hometown of Ningbo, east China＇s Zhejiang Province.
文摘This paper presents the design and manufacture process of a wheel-less,modular snake robot with series elastic actuators to reliably measure motor torque signal and investigate the effectiveness of active stiffness control for achieving adaptive snake-like locomotion.A polyurethane based elastic element to be attached between the motor and the links at each joint was designed and manufactured using water jet cutter,which makes the final design easier to develop and more cost-effective,compared to existing snake robots with torque measurement capabilities.The reliability of such torque measurement mechanism was examined using simulated dynamical model of pedal wave motion,which proves the efficacy of the design.A distributed control system was also designed,which with the help of an admittance controller,enables active control of the joint stiffness to achieve adaptive snake robot pedal wave locomotion to climb over obstacles,which unlike existing methods does not require prior information about the location of the obstacle.The effectiveness of the proposed controller in comparison to open-loop control strategy was verified by the number of experiments.The results show the capability of the robot to successfully climb over obstacles with the height of more than 55%of the diameter of the snake robot modules.
