Estimation of Occluded Lower Limb Using Inverted Pendulum Model

2013 ◽  
Vol 284-287 ◽  
pp. 2056-2063
Author(s):  
Hian Kun Tenn ◽  
Yao Yang Tsai

For many interactive vision based systems, users are captured by the system and modeled as a simplified skeleton. The skeleton model usually encounter problems of occlusion because of obstacles or other users appearing in the environment. In this paper, we proposed a method based on an inverted pendulum model (IPM), which was applied to recover the occluded leg of skeleton model. The skeleton model was provided by Vicon motion measurement system, which captured the participant's motions. One leg of the skeleton model was removed intentionally and the proposed method was used to estimate the pose of the occluded leg in real-time. The results showed that most of the positioning errors were within 10 cm on average and the processing rate exceeded 100 fps.

Robotica ◽  
2014 ◽  
Vol 32 (6) ◽  
Author(s):  
Dongil Choi ◽  
Jun-ho Oh

SUMMARYThis paper introduces a novel approach to motion planning for a rapid mobile manipulator using inverted pendulum models. Our aim was to realize an actual rapid mobile manipulator with high acceleration and speed performance for an object's delivery. In our research, we developed an actual rapid mobile manipulator called KDMR-1. We proposed simple motion planning methods using a single inverted pendulum model (SIPM) and a double inverted pendulum model (DIPM), which are easily adaptable to a real-time system with only a small computational burden. The SIPM was useful for basic movement but did not provide object carrying capability. For that, a DIPM was proposed. In both models, we designed linear quadratic optimal controllers to stabilize the Zero Moment Point (ZMP). Two kinds of ZMP stabilization strategies were proposed, fixed ZMP and relaxed ZMP. Using these strategies, we realized optimal ZMP stabilizations for a real-time rapid mobile manipulator. For decoupled forward and rotational linear DIPM, we designed a centrifugal acceleration compensation model in the manner of feedback linearization. The experimental results showed high acceleration and speed performances during rapid object delivery.


2010 ◽  
Vol 16 (2) ◽  
pp. 325-337 ◽  
Author(s):  
Yao-Yang Tsai ◽  
Wen-Chieh Lin ◽  
K.B. Cheng ◽  
Jehee Lee ◽  
Tong-Yee Lee

1999 ◽  
Vol 354 (1385) ◽  
pp. 869-875 ◽  
Author(s):  
E. Otten

The balance of standing humans is usually explained by the inverted pendulum model. The subject invokes a horizontal ground–reaction force in this model and controls it by changing the location of the centre of pressure under the foot or feet. In experiments I showed that humans are able to stand on a ridge of only a few millimetres wide on one foot for a few minutes. In the present paper I investigate whether the inverted pendulum model is able to explain this achievement. I found that the centre of mass of the subjects sways beyond the surface of support, rendering the inverted pendulum model inadequate. Using inverse simulations of the dynamics of the human body, I found that hip–joint moments of the stance leg are used to vary the horizontal component of the ground–reaction force. This force brings the centre of mass back over the surface of support. The subjects generate moments of force at the hip–joint of the swing leg, at the shoulder–joints and at the neck. These moments work in conjunction with a hip strategy of the stance leg to limit the angular acceleration of the head–arm–trunk complex. The synchrony of the variation in moments suggests that subjects use a motor programme rather than long latency reflexes.


2018 ◽  
Vol 8 (8) ◽  
pp. 1257 ◽  
Author(s):  
Tianqi Yang ◽  
Weimin Zhang ◽  
Xuechao Chen ◽  
Zhangguo Yu ◽  
Libo Meng ◽  
...  

The most important feature of this paper is to transform the complex motion of robot turning into a simple translational motion, thus simplifying the dynamic model. Compared with the method that generates a center of mass (COM) trajectory directly by the inverted pendulum model, this method is more precise. The non-inertial reference is introduced in the turning walk. This method can translate the turning walk into a straight-line walk when the inertial forces act on the robot. The dynamics of the robot model, called linear inverted pendulum (LIP), are changed and improved dynamics are derived to make them apply to the turning walk model. Then, we expend the new LIP model and control the zero moment point (ZMP) to guarantee the stability of the unstable parts of this model in order to generate a stable COM trajectory. We present simulation results for the improved LIP dynamics and verify the stability of the robot turning.


Sign in / Sign up

Export Citation Format

Share Document