MHS measure for postural stability monitoring and control of biped robots

Takhmar, Amir; Asif, Mansoor; Alipour, Khalil; Ali, Syed Saad Azhar; Moosavian, S. Ali A.

doi:10.1109/aim.2008.4601694

Cited by 8 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been exploited for postural stability examination of mobile manipulators with rigid elements and wheeled mobile manipulators with flexible suspension, [20]. The MHS measure has been also effectively used for legged robots, [24].…”

Section: A Brief Review Of the Moment-height Stability Measurementioning

confidence: 99%

Dynamics and stability of a hybrid serial-parallel mobile robot

Moosavian

Pourreza

Alipour

2010

Mathematical and Computer Modelling of Dynamical Systems

Self Cite

View full text Add to dashboard Cite

Kinematics, dynamics, and stability analysis of a hybrid serial-parallel wheeled mobile robot is detailed in this paper. Privileging the advantages of both serial and parallel robots, the suggested structure will provide higher stability for heavy object manipulation by a mobile robotic system. The proposed system is made of a differentially-driven wheeled platform, a planar parallel manipulator, which is called here as star-triangle (ST) mechanism, and a serial Puma-type manipulator arm. In order to develop a comprehensive kinematics model of the robot; first it is divided into three modules, i.e. a mobile platform, a parallel ST mechanism, and a serial robot. Next, a closed-form dynamics model is derived for the whole hybrid system based on a combined Newton-Euler and Lagrange formulation. Then, a careful validation procedure is presented to verify the obtained dynamics model. Finally, using the new postural stability metric named as moment-height stability (MHS), the important role of the parallel ST mechanism for stabilizing the mobile robotic system is demonstrated. The obtained results show that the proposed hybrid serial-parallel arrangement effectively enhances the tip-over stability of the overall mobile robotic system. Hence, it can be successfully exploited to prevent tip-over instability particularly during heavy object manipulation tasks.

show abstract

Section: A Brief Review Of the Moment-height Stability Measurementioning

confidence: 99%

Dynamics and stability of a hybrid serial-parallel mobile robot

Moosavian

Pourreza

Alipour

2010

Mathematical and Computer Modelling of Dynamical Systems

Self Cite

View full text Add to dashboard Cite

show abstract

“…Center of mass stability, 31 energy-based stability, 32 and zero moment point (ZMP) criterion are the most important stability criteria in this realm. 33 If the robots have active joints, and in each moment stand on one leg, ZMP can be applied regarding stability assessment. This criterion was taken into account for the bipedal robot in Vasda University and then has been widely employed.…”

Section: Introductionmentioning

confidence: 99%

Hybrid Adaptive Robust Control Based on CPG and ZMP for a Lower Limb Exoskeleton

2020

View full text Add to dashboard Cite

SUMMARY In this paper, hybrid control of central pattern generators (CPGs), along with an adaptive supper-twisting sliding mode (ASTSM) control based on supper-twisting state observer, is proposed to guard against disturbances and uncertainties. Rhythmic and coordinated signals are generated using CPGs. In addition, to overcome the chattering of conventional sliding mode, supper-twisting sliding mode has been applied. The ASTSM method triggers sliding variables, and its derivatives tend to zero continuously in the presence of the uncertainties. Moreover, to acquire maximum stability, the desired trajectory of the upper limb based on zero moment point criterion is designed.

show abstract

“…The Moment-Height stability (MHS) measure which has been originally presented as a stability measure for wheeled mobile robots, 5,6 was also developed for biped robots postural stability investigation. 7 The MHS metric is physically meaningful based on principal concepts and can be implemented with low computational effort.…”

Section: Introductionmentioning

confidence: 99%

Cartesian Approach for Gait Planning and Control of Biped Robots on Irregular Surfaces

Moosavian

Asif

Takhmar

2009

Int. J. Human. Robot.

Self Cite

View full text Add to dashboard Cite

Biped robots possess higher capabilities than other mobile robots for moving on uneven environments. However, due to natural postural instability of these robots, their motion planning and control become a more important and challenging task. This article presents a Cartesian approach for gait planning and control of biped robots without the need to use the inverse kinematics and the joint space trajectories, thus the proposed approach could substantially reduce the processing time in both simulation studies and online implementations. It is based on constraining four main points of the robot in Cartesian space. This approach exploits the concept of Transpose Jacobian control as a virtual spring and damper between each of these points and the corresponding desired trajectory, which leads to overcome the redundancy problem. These four points include the tip of right and left foot, the hip joint, and the total center of mass (CM). Furthermore, in controlling biped robots based on desired trajectories in the task space, the system may track the desired trajectory while the knee is broken. This problem is solved here using a PD controller which will be called the Knee Stopper. Similarly, another PD controller is proposed as the Trunk Stopper to limit the trunk motion. Obtained simulation results show that the proposed Cartesian approach can be successfully used in tracking desired trajectories on various surfaces with lower computational effort.

show abstract

MHS measure for postural stability monitoring and control of biped robots

Cited by 8 publications

References 11 publications

Dynamics and stability of a hybrid serial-parallel mobile robot

Dynamics and stability of a hybrid serial-parallel mobile robot

Hybrid Adaptive Robust Control Based on CPG and ZMP for a Lower Limb Exoskeleton

Cartesian Approach for Gait Planning and Control of Biped Robots on Irregular Surfaces

Contact Info

Product

Resources

About