Walking Pattern Filter for Dynamic Biped Robot With SMA Actuators

Aerospace ◽  
2006 ◽  
Author(s):  
E. Tarkesh Esfahani ◽  
Mohammad Elahinia
Keyword(s):  
Biped Robot ◽  
Human Motion ◽  
Main Criterion ◽  
Biped Robots ◽  
Sma Actuators ◽  
Walking Pattern ◽  
Delay Times ◽  
Zero Moment ◽  
The Stability ◽  
The Given

In this paper we present a walking pattern filter for Shape Memory Alloy (SMA) actuated biped robots. SMAs are known for their slow response. The actuation speed limitation can potentially lead to stability problems for biped robots. This filter adapts the human motion for a SMA biped in order to have a stable walking pattern. The Zero Moment Point (ZMP) is used as a main criterion of the filter to guarantee the stability of the motion. The SMA actuators are designed based on the dynamic and kinematics data of the motion. The response time of each SMA actuator is modeled in order to estimate the behavior of the actuator in realizing the given trajectory. After applying the delay times to the motion new trajectories are generated and checked by the ZMP criterion. The output of the filter can generate smooth trajectories for the SMA biped robots. The filter furthermore guarantees the stability while mimicking the human motion. The filter provides a practical way to create stable walking patterns using SMA actuators.

PLANNING OF SAGITTAL GAIT OF BIPED ROBOTS BASED ON MINIMUM MOTION ENERGY

2010 ◽  
Vol 07 (04) ◽  
pp. 635-667 ◽  
Author(s):  
KUO-YANG TU ◽  
MI-SHIN LIU
Keyword(s):  
Lower Limb ◽  
Optimal Trajectory ◽  
Biped Robot ◽  
Inverse Kinematic ◽  
Biped Robots ◽  
Motion Energy ◽  
Walking Pattern ◽  
Acceleration And Deceleration ◽  
Zero Moment ◽  
Kinetic And Potential Energies

Traditional planning of biped robot walking patterns solves optimal trajectory for minimizing energy consumption. However, a diversity of biped robot walking functions lead to a variety of walking types. The walking patterns to implement a variety of biped robot objectives should have enough parameters to cope with their functions. In this article, walking patterns based on two 4-3-4 polynomials for the trajectories of biped robot waist and lower limb are proposed. The main advantage of the walking pattern is that 4-3-4 polynomials containing the parameters of acceleration and deceleration for biped walking make the implementation of a variety of walking types possible. In the study, the prototype mechanism of a biped robot is designed. After that, the direct and inverse kinematic equations of the biped robot are derived. For studying motion energy of biped robots, kinetic and potential energies are also defined. Based on these definitions, the parameters of the biped robot trajectories for minimum motion energy are solved. The solution is summarized by a development procedure. In addition, the study of zero moment point (ZMP) during the biped robot in walking is included.

WALKING PATTERN MAPPING FROM IMPERFECT MOTION CAPTURE DATA ONTO BIPED HUMANOID ROBOTS

2010 ◽  
Vol 07 (01) ◽  
pp. 127-156 ◽  
Author(s):  
JUNG-YUP KIM ◽  
YOUNG-SEOG KIM
Keyword(s):  
Motion Capture ◽  
Measurement Errors ◽  
Biped Robot ◽  
Humanoid Robots ◽  
Mapping Method ◽  
Human Motion ◽  
Motion Capture Data ◽  
Biped Robots ◽  
Walking Pattern ◽  
Walking Motion

This paper proposes an efficient walking pattern mapping algorithm from motion capture data onto biped humanoid robots. Currently, the technology known as human motion capture is widely utilized to generate various humanlike motions in many applications, including robotics. An important thing is that several difficulties are associated with motion capture data. These include a data offset issue, noise, and drift problems due to measurement errors caused by imperfect camera calibration, and marker position. If a biped robot uses motion capture data without suitable post-processes, the walking motion of the robot will differ from an actual walking motion, and the Zero Moment Point (ZMP) will be asymmetrical and noisy, leading to unstable walking. A further difficulty exists in the walking pattern mapping process due to the different joint numbers, link sizes, and weights between a human and a robot. Although walking pattern mapping is suitable after addressing the above difficulties, a slip problem between the feet and the ground can continue to cause problems. To solve these difficulties efficiently, a Fourier fitting method is proposed in this research. Improvements of walking pattern and the ZMP trajectory are confirmed using the proposed method. Furthermore, a geometric mapping method is introduced to generate walking patterns for various biped robots while maintaining a degree of similarity to humans. By applying a no-slip constraint to the feet and modifying the joint angles through inverse kinematics, the slip problem is also solved. The effectiveness of the proposed algorithm is verified through computer simulations of two different biped robots that have different sizes, weights, walking cycles, and step lengths.

Biped Landing Pattern Modification Method and Walking Experiments in Outdoor Environment

2008 ◽  
Vol 20 (5) ◽  
pp. 775-784 ◽  
Author(s):  
Kenji Hashimoto ◽  
◽  
Yusuke Sugahara ◽  
Hun-Ok Lim ◽  
Atsuo Takanishi ◽  
...  
Keyword(s):  
Biped Robot ◽  
Stability Control ◽  
Outdoor Environment ◽  
Walking Robots ◽  
Control Algorithms ◽  
Biped Robots ◽  
Uneven Terrain ◽  
Walking Pattern ◽  
Actual Compliance ◽  
Modification Method

Many researchers have studied walking stability control for biped robots, most of which involve highly precise acceleration controls based on robot model mechanics. Modeling error, however, makes the control algorithms used difficult to apply to biped walking robots intended to transport human users. The “landing pattern modification method” we propose is based on nonlinear admittance control. Theoretical compliance displacement calculated from walking patterns is compared to actual compliance displacement, when a robot's foot contacts slightly uneven terrain. Terrain height is detected and the preset walking pattern is modified accordingly. The new biped foot we also propose forms larger support polygons on uneven terrain than conventional biped foot systems do. Combining our new modification method and foot, a human-carrying biped robot can traverse uneven terrain, as confirmed in walking experiments.

scholarly journals Trajectory Planning and Walking Pattern Generation of Humanoid Robot Motion

2014 ◽  
Vol 4 (2) ◽  
pp. 135
Author(s):  
Saeed Abdolshah ◽  
Majid Abdolshah ◽  
Sai Hong Tang
Keyword(s):  
Inverse Kinematics ◽  
Humanoid Robot ◽  
Human Motion ◽  
Pattern Generation ◽  
Robot Motion ◽  
Simulation Environment ◽  
Walking Pattern ◽  
Walking Pattern Generation ◽  
Zero Moment ◽  
Geometrical Relationships

Walking trajectory generation for a humanoid robot is a challenging control  issue. In this paper, a walking cycle has been recognized considering human motion, and nine simple steps were distinguished in a full step of walking which form motion trajectory, and generates a simplified ZMP motion formulation. This system was used in humanoid robot simulation motion and is achievable easily in walking steps of robot. A minimum DOFs humanoid robot has been considered and geometrical relationships between the robot links were presented by the Denavit-Hartenberg method. The inverse kinematics equations have been solved regarding to extracted ZMP trajectory formula, and constraints in different steps. As a result; angular velocity, acceleration and power of motors were obtained using the relationships and Jacobin. At each step, extracted data were applied on simulated robot in Matlab, and Visual Nastran software. Zero moment point trajectory was evaluated in simulation environment.

Modeling, stability and walking pattern generators of biped robots: a review

Robotica ◽  
2013 ◽  
Vol 32 (6) ◽  
pp. 907-934 ◽  
Author(s):  
Hayder F. N. Al-Shuka ◽  
F. Allmendinger ◽  
B. Corves ◽  
Wen-Hong Zhu
Keyword(s):  
Artificial Intelligence ◽  
Control Strategies ◽  
Biped Robot ◽  
Human Locomotion ◽  
Biped Robots ◽  
Walking Pattern ◽  
Control Electronics ◽  
The Subject ◽  
Pattern Generators

SUMMARYBiped robots have gained much attention for decades. A variety of researches have been conducted to make them able to assist or even substitute for humans in performing special tasks. In addition, studying biped robots is important in order to understand human locomotion and to develop and improve control strategies for prosthetic and orthotic limbs. This paper discusses the main challenges encountered in the design of biped robots, such as modeling, stability and their walking patterns. The subject is difficult to deal with because the biped mechanism intervenes with mechanics, control, electronics and artificial intelligence. In this paper, we collect and introduce a systematic discussion of modeling, walking pattern generators and stability for a biped robot.

Gait motion stabilization tuning approach of biped robot based on augmented reality

Robotica ◽  
2013 ◽  
Vol 32 (3) ◽  
pp. 325-339 ◽  
Author(s):  
J. Lin ◽  
Z. M. Li ◽  
J. Chang
Keyword(s):  
Augmented Reality ◽  
Software Package ◽  
Joint Angle ◽  
Computer Software ◽  
Biped Robot ◽  
Angle Data ◽  
Before And After ◽  
Motion Stabilization ◽  
Zero Moment ◽  
The Stability

SUMMARYZero moment point (ZMP) is the most popular concept that is applied to stabilize the gait motion of a biped robot. This paper utilizes ZMP with the augmented-reality (AR) method to improve the stability of gait motion of a biped robot. The 3ds Max computer software package is used to build a virtual robot. Under an achieved joint angle data of solid robot to produce an animation of the robot's trajectory, the joint angle data are transmitted to the virtual robot to analyze the offset of the trunk. Furthermore, this investigation adopts AR to allow the user to make direct comparisons between the solid and virtual robot before and after the gait motion is corrected. The animated trajectories of the virtual robot are compared and the relevant data provide feedback to the solid robot to adjust the joint angle and further correct its posture. The experimental results reveal that the proposed scheme can improve gait motion, even when the biped robot is affected by an unexpected loading disturbance. As well as improving the stability of gait motion of a biped robot, the results of this study can also be used to teach the application of the proposed method in a robotics class.

Design of a Biped Toy Robot with an Automatic Center of Gravity Shifting Mechanism

2010 ◽  
Vol 118-120 ◽  
pp. 670-674
Author(s):  
Pai Shan Pa ◽  
Jinn Bao Jou
Keyword(s):  
Degrees Of Freedom ◽  
Biped Robot ◽  
Center Of Gravity ◽  
Biped Robots ◽  
Zero Moment Point ◽  
Single Motor ◽  
Mechanical Products ◽  
Zero Moment ◽  
Crank Mechanism

The design of the biped toy robot in this study, presents a brand new concept compared to that of the conventional mechanical biped robots on the market. These conventional mechanical products rely mainly on a large sole area to stabilize the wobbling movement during walking. In this design walking stability is not achieved by large sole areas, but by having more degrees of freedom and automatically shifting the center of gravity as the robot walks. A single motor is used to drive the biped toy robot trunk so that the center of gravity is automatically shifted to achieve walking stability. The two feet are driven by four connecting rods for striding and leg-lifting action. More particularly, an equal parallel crank mechanism is provided that uses a single motor to drive the connecting rods, thereby swinging the center of gravity of the toy robot in time with striding frequency. In addition, the concept of the zero moment point is utilized in the shifting of the center of gravity allowing the biped robot to lift its legs, change step, and move forward in balance. This study also discusses the use of the four connecting rods, and the shifting of the center of gravity of the robot, as an alternative to the servomotors commonly used in conventional robots which are bulky, expensive and hard to control.

GA Based Trajectory Generation for a 7-DOF Biped Robot by Considering Feet Rotation during Double Support Phase

2012 ◽  
Vol 463-464 ◽  
pp. 1252-1255 ◽  
Author(s):  
Farsam Farzadpour ◽  
Mohammad Danesh
Keyword(s):  
High Speed ◽  
Trajectory Generation ◽  
Biped Robot ◽  
Bipedal Walking ◽  
Double Support ◽  
Straight Line ◽  
Zero Moment ◽  
The Stability ◽  
Support Phase ◽  
Double Support Phase

This paper presents a trajectory generation approach for a 7-DOF biped robot on level ground. Simultaneously rotation of feet in double support phase is considered which leads to high-speed and more similar to human being walking. The zero moment point (ZMP) stability criterion is used to ensure the stability of the bipedal walking robot. Since ZMP trajectory in human walking does not stay fixed, it needs to be a straight line shaped forward ZMP trajectory to have a natural walk. A genetic algorithm based method is proposed to obtain key parameters in trajectory generation such that the ZMP follows a predefined trajectory while minimizing power consumption. Simulation results demonstrate the effectiveness of the proposed method.

Tip over avoidance control for biped robot

Robotica ◽  
2009 ◽  
Vol 27 (6) ◽  
pp. 883-889 ◽  
Author(s):  
Tang Qing ◽  
Xiong Rong ◽  
Chu Jian
Keyword(s):  
Inverted Pendulum ◽  
Biped Robot ◽  
Point Of View ◽  
Experimental Results ◽  
Stabilization Problem ◽  
Point Energy ◽  
Energy Point ◽  
Walking Pattern ◽  
Avoidance Control ◽  
Zero Moment

SUMMARYThis paper analyzes the stabilization problem from the energy point of view. Perturbations are detected by the gyros and categorized according to the constraints on the zero-moment point, energy, and walking pattern. Ankle torque is exerted to extend the linear inverted pendulum mode (LIPM). Compensation movement is computed according to the analysis on the energy of LIPM and the influence of disturbance to the energy. The experimental results from both the simulation and the physical robot not only proved effective but also explain various human reactions to disturbance in locomotion.

Rotational Stability Index (RSI) point: postural stability in planar bipeds

Robotica ◽  
2010 ◽  
Vol 29 (5) ◽  
pp. 705-715 ◽  
Author(s):  
Goswami Dip ◽  
Vadakkepat Prahlad
Keyword(s):  
Postural Stability ◽  
Stability Index ◽  
Rotational Stability ◽  
Stability Criteria ◽  
Flat Foot ◽  
Biped Robots ◽  
Zero Moment Point ◽  
Foot Posture ◽  
Zero Moment ◽  
The Stability

SUMMARYThe postural stability of bipedal robots is investigated in perspective of foot-rotation during locomotion. With foot already rotated, the biped is modeled as an underactuated kinematic structure. The stability of such biped robots is analyzed by introducing the concept of rotational stability. The rotational stability investigates whether a biped would lead to a flat-foot posture or the biped would topple over. The rotational stability is quantified as a ground reference point named “rotational stability index (RSI)” point. Conditions are established to achieve rotational stability during biped locomotion using the concept of the RSI point. The applicability of the RSI point is illustrated through experimentation for the landing stability analysis of the bipedal jumping gaits.The traditional stability criteria such as zero-moment point (ZMP) [M. Vukobratovic and B. Borovac, “Zero-moment point – thirty five years of its life,” Int. J. Humanoid Robot. 1(1), 157–173 (2004)] and foot-rotation indicator (FRI) [A. Goswami, “Postural stability of biped robots and the foot-rotation indicator (FRI) point,” Int. J. Robot. Res. 18(6), 523–533 (1999)] are not applicable to analyze biped's postural stability when foot is already rotated. The RSI point is established as a stability criteria for planar bipedal locomotion in presence of foot rotation.

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