Dynamic heel-strike toe-off walking controller for full-size modular humanoid robots

2016 ◽  
Author(s):  
Seung-Joon Yi ◽  
Daniel D. Lee
Keyword(s):  
Humanoid Robots ◽  
Heel Strike ◽  
Full Size

Heel-strike and toe-off motions optimization for humanoid robots equipped with active toe joints

Robotica ◽  
2018 ◽  
Vol 36 (6) ◽  
pp. 925-944 ◽  
Author(s):  
Majid Sadedel ◽  
Aghil Yousefi-Koma ◽  
Majid Khadiv ◽  
Faezeh Iranmanesh
Keyword(s):  
Energy Consumption ◽  
Friction Coefficient ◽  
Dynamic Model ◽  
Humanoid Robot ◽  
Optimization Procedure ◽  
Humanoid Robots ◽  
Joint Torque ◽  
Heel Strike ◽  
Walking Pattern ◽  
Goal Functions

SUMMARYIn this paper, a walking pattern optimization procedure is implemented to yield the optimal heel-strike and toe-off motions for different goal functions. To this end, first, a full dynamic model of a humanoid robot equipped with active toe joints is developed. This model consists of two parts: multi-body dynamics of the robot which is obtained by Lagrange and Kane methods and power transmission dynamic model which is developed using system identification approach. Then, a gait planning routine is presented and consistent parameters are specified. Several simulations and experimental tests are carried out on SURENA III humanoid robot which is designed and fabricated at the Center of Advanced Systems and Technologies located in the University of Tehran. Afterward, a genetic algorithm optimization is adopted to compute the optimal walking patterns for five different goal functions including energy consumption, stability margin, joint velocity, joint torque and required friction coefficient. Also, several parametric analyses are performed to characterize the effects of heel-strike and toe-off angle and toe link mass and length on these five goal functions. Finally, it is concluded that walking pattern without heel-strike and toe-off motions requires less friction coefficient than the pattern with heel-strike and toe-off motions. Also, heavier toe link lowers tip-over instability and slippage occurrence possibility, but requires more energy consumption and joint torque.

Towards dynamically consistent real-time gait pattern generation for full-size humanoid robots

2013 ◽  
Author(s):  
Przemyslaw Kryczka ◽  
Yukitoshi Minami Shiguematsu ◽  
Petar Kormushev ◽  
Kenji Hashimoto ◽  
Hun-ok Lim ◽  
...  
Keyword(s):  
Real Time ◽  
Humanoid Robots ◽  
Gait Pattern ◽  
Pattern Generation ◽  
Full Size

INNOVATIVE FOOT PRESSURE SENSOR DESIGN FOR HUMANOID ROBOTS

2019 ◽  
Author(s):  
FRANCISCO ARTHUR BONFIM AZEVEDO ◽  
Daniela Vacarini de Faria ◽  
Marcos Maximo ◽  
Mauricio Donadon
Keyword(s):  
Pressure Sensor ◽  
Humanoid Robots ◽  
Sensor Design ◽  
Foot Pressure

LUKENS TOOL STEELS

Alloy Digest ◽  
1997 ◽  
Vol 46 (2) ◽  
Keyword(s):  
Tool Steel ◽  
Cold Work ◽  
Tool Steels ◽  
Steel Company ◽  
Full Size ◽  
Heat Treated

Abstract Lukens cold-work tool steels A2, D2, O1, S5, and S7 are used in applications where an air-hardening, oil-hardening, or shock-resisting tool steel is required. These steels are available in full-size, annealed plates suitable for saw cutting and/or finishing. Parts can subsequently be machined and heat treated to a range of hardness requirements. For improved internal cleanliness, all Lukens cold-work tool steels are produced with maximum sulfur levels of 0.010%. This datasheet provides information on composition. It also includes information on machining and joining. Filing Code: TS-550. Producer or source: Lukens Steel Company.

Compact specification of polar codes

2019 ◽  
pp. 40-47
Author(s):  
R. A. Morozov ◽  
P. V. Trifonov
Keyword(s):  
Storage Capacity ◽  
Low Complexity ◽  
Practical Implementation ◽  
Polar Codes ◽  
Practical Relevance ◽  
Memory Consumption ◽  
Full Size ◽  
The Family ◽  
Erasure Probability ◽  
Binary Erasure Channel

Introduction:Practical implementation of a communication system which employs a family of polar codes requires either to store a number of large specifications or to construct the codes by request. The first approach assumes extensive memory consumption, which is inappropriate for many applications, such as those for mobile devices. The second approach can be numerically unstable and hard to implement in low-end hardware. One of the solutions is specifying a family of codes by a sequence of subchannels sorted by reliability. However, this solution makes it impossible to separately optimize each code from the family.Purpose:Developing a method for compact specifications of polar codes and subcodes.Results:A method is proposed for compact specification of polar codes. It can be considered a trade-off between real-time construction and storing full-size specifications in memory. We propose to store compact specifications of polar codes which contain frozen set differences between the original pre-optimized polar codes and the polar codes constructed for a binary erasure channel with some erasure probability. Full-size specification needed for decoding can be restored from a compact one by a low-complexity hardware-friendly procedure. The proposed method can work with either polar codes or polar subcodes, allowing you to reduce the memory consumption by 15–50 times.Practical relevance:The method allows you to use families of individually optimized polar codes in devices with limited storage capacity. 

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