scholarly journals Exponential Stabilization of Fully Actuated Planar Bipedal Robotic Walking With Global Position Tracking Capabilities

Author(s):  
Yan Gu ◽  
Bin Yao ◽  
C. S. George Lee

This paper focuses on the development of a model-based feedback controller to realize high versatility of fully actuated planar bipedal robotic walking. To conveniently define both symmetric and asymmetric walking patterns, we propose to use the left and the right legs for gait characterization. In addition to walking pattern tracking error, a biped's position tracking error in Cartesian space is included in the output function in order to enable high-level task planning and control such as multi-agent coordination. A feedback controller based on input–output linearization and proportional–derivative control is then synthesized to realize exponential tracking of the desired walking pattern as well as the desired global position trajectory. Sufficient stability conditions of the hybrid time-varying closed-loop system are developed based on the construction of multiple Lyapunov functions. In motion planning, a new method of walking pattern design is introduced, which decouples the planning of global motion and walking pattern. Finally, simulation results on a fully actuated planar biped show the effectiveness of the proposed walking strategy.

2018 ◽  
Vol 66 (2) ◽  
pp. 160-182
Author(s):  
Benjamin C. Heinrich ◽  
Thorsten Luettel ◽  
Dennis Fassbender ◽  
Patrick Burger ◽  
Felix Ebert ◽  
...  

AbstractIn this paper, we describe the hardware and software components of a fully autonomous prototype delivery vehicle. Equipped with a robotic arm, the demonstrator is capable of delivering packages and picking up new ones by interacting with custom-made delivery boxes. As highly accurate positioning w. r. t. a box is required for successful handover of packages, we track the pose (position and orientation) of the box using a high-resolution on-board camera. The resulting estimate is relayed to our planning and control modules, which ensure that the vehicle reaches its required pose with centimeter-level accuracy.In order to deliver packages, the car needs to autonomously navigate our test facility, avoiding static and dynamic obstacles while obeying simple traffic rules. As one focus is on the practical challenges encountered when building a prototype, we cover issues ranging from sensor calibration and system identification to perception, planning, control, and the implementation of high-level behaviors. While some of the proposed solutions to these problems are not necessarily novel, they allowed us to demonstrate the vehicle’s capabilities after a development phase of less than 12 months.


Author(s):  
Lihui Wang ◽  
Weiming Shen ◽  
Xiaoqian Li ◽  
Sherman Lang

The objective of this research is to develop methodology and framework for distributed shop floor planning, real-time monitoring, and remote device control supported by intelligent sensors. An intelligent sensor serves runtime data from bottom up to facilitate high-level decision-making. It assures that correct decisions are made in a timely manner, if compared with the best estimations of engineers. Being an adaptive system, a so-designed framework will improve the flexibility and dynamism of shop floor operations, and provide a seamless integration among process planning, resource scheduling, job execution, process monitoring, and device control. This paper presents principles of the methodology, details in architecture design, module interactions, information flow, and a proof-of-concept prototype implementation.


AI Magazine ◽  
2013 ◽  
Vol 34 (3) ◽  
Author(s):  
Lara S. Crawford

A recent trend in intelligent machines and manufacturing has been toward reconfigurable manufacturing systems, which move away from the idea of a fixed factory line executing an unchanging set of operations, and toward the goal of an adaptable factory structure. The logical next challenge in this area is that of on-line reconfigurability. With this capability, machines can reconfigure while running, enable or disable capabilities in real time, and respond quickly to changes in the system or the environment (including faults). We propose an approach to achieving on-line reconfigurability based on a high level of system modularity supported by integrated, model-based planning and control software. Our software capitalizes on many advanced techniques from the artificial intelligence research community, particularly in model-based domain-independent planning and scheduling, heuristic search, and temporal resource reasoning. We describe the implementation of this design in a prototype highly modular, parallel printing system.


2011 ◽  
Vol 28 (03) ◽  
pp. 301-322 ◽  
Author(s):  
ABHIJEET SINGH ◽  
SAROJ KOUL ◽  
ANIL K. AGRAWAL

Joint economic lot size models for purchasers and vendors are more economical than when considering their inventory problems independently. It requires vendors to have a complete knowledge of their purchaser's demands. In such a situation, the vendor shall manage the supply with comparatively more inventory at its end. The operational cost can further decrease provided supply is in sub-batches and logistics cost does not increase substantially. However, determining the right size for these sub-batches becomes an issue. Sub-batches of varying size may cause planning and control problems, but supply in sub-batches of uniform size will not. In this paper, joint economic lot size models are presented for the two supply situations, namely staggered supply and uniform supply. Cases are employed that describe the inventory situation of a single vendor supplying an item to a manufacturer that is further processed before it is supplied to the end-user. Using illustrative examples, the comparative advantages of the uniform sub-batch supply over the staggered alternative are investigated. From the analysis, uniform supply models are found to be comparatively more beneficial and robust than the staggered sub-batch supply.


2016 ◽  
Vol 38 (12) ◽  
pp. 1520-1534 ◽  
Author(s):  
Xiangyu Wang ◽  
Guipu Li ◽  
Shihua Li ◽  
Aiguo Song

In this paper, the position tracking control problem of pneumatic servo systems is investigated. These systems usually have high nonlinearities and unmeasurable piston velocities. Firstly, by using adding a power integrator technique, a global finite-time state feedback controller is proposed. Secondly, based on homogeneous theory, a nonlinear observer is developed to estimate the piston velocity. Finally, the corresponding output feedback controller is derived, which local finite-time stabilizes the position tracking error system. Compared with the conventional backstepping output feedback control scheme, the developed nonsmooth output feedback control scheme offers a faster convergence rate and a better disturbance rejection property. Numerical simulations illustrate the effectiveness of the proposed control scheme.


AI Magazine ◽  
2013 ◽  
Vol 34 (3) ◽  
pp. 73-88 ◽  
Author(s):  
Lara S. Crawford ◽  
Minh Binh Do ◽  
Wheeler S. Ruml ◽  
Haitham Hindi ◽  
Craig Eldershaw ◽  
...  

A recent trend in intelligent machines and manufacturing has been toward reconfigurable manufacturing systems, which move away from the idea of a fixed factory line executing an unchanging set of operations, and toward the goal of an adaptable factory structure. The logical next challenge in this area is that of on-line reconfigurability. With this capability, machines can reconfigure while running, enable or disable capabilities in real time, and respond quickly to changes in the system or the environment (including faults). We propose an approach to achieving on-line reconfigurability based on a high level of system modularity supported by integrated, model-based planning and control software. Our software capitalizes on many advanced techniques from the artificial intelligence research community, particularly in model-based domain-independent planning and scheduling, heuristic search, and temporal resource reasoning. We describe the implementation of this design in a prototype highly modular, parallel printing system.


2014 ◽  
Vol 26 (1) ◽  
pp. 16-27 ◽  
Author(s):  
Lucina Q. Uddin ◽  
Joshua Kinnison ◽  
Luiz Pessoa ◽  
Michael L. Anderson

Functional MRI studies report insular activations across a wide range of tasks involving affective, sensory, and motor processing, but also during tasks of high-level perception, attention, and control. Although insular cortical activations are often reported in the literature, the diverse functional roles of this region are still not well understood. We used a meta-analytic approach to analyze the coactivation profiles of insular subdivisions—dorsal anterior, ventral anterior, and posterior insula—across fMRI studies in terms of multiple task domains including emotion, memory, attention, and reasoning. We found extensive coactivation of each insular subdivision, with substantial overlap between coactivation partners for each subdivision. Functional fingerprint analyses revealed that all subdivisions cooperated with a functionally diverse set of regions. Graph-theoretical analyses revealed that the dorsal anterior insula was a highly “central” structure in the coactivation network. Furthermore, analysis of the studies that activate the insular cortex itself showed that the right dorsal anterior insula was a particularly “diverse” structure in that it was likely to be active across multiple task domains. These results highlight the nuanced functional profiles of insular subdivisions and are consistent with recent work suggesting that the dorsal anterior insula can be considered a critical functional hub in the human brain.


2021 ◽  
Vol 93 (3) ◽  
pp. 665-699
Author(s):  
Darija Martinov

Positive obligations are obligations of the Member States of the European Convention for the Protection of Human Rights and Fundamental Freedoms to take active steps to protect the rights guaranteed by this Convention. When it comes to the protection of the right to life, as one of the basic human rights, the case of McCann and Others v. the United Kingdom set a precedent and established new obligations for States party to the Convention when it comes to planning and conducting law enforcement operations. The manner in which these obligations were established, their scope and content, as well as the comments from jurisprudence and practitioners on this innovative judgment, are the subject of the analysis of this paper.


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