scholarly journals Energy Implications of Torque Feedback Control and Series Elastic Actuators for Mobile Robots

2018 ◽  
Author(s):  
Stephen P. Buerger ◽  
Anirban Mazumdar ◽  
Steven J. Spencer
Keyword(s):  
Energy Consumption ◽  
Feedback Control ◽  
Best Practices ◽  
Energy Efficient ◽  
Mechanical Impedance ◽  
Gear Ratio ◽  
Spring Stiffness ◽  
Feedback Analysis ◽  
Series Elastic Actuators ◽  
Series Elastic

Torque feedback control and series elastic actuators are widely used to enable compact, highly-geared electric motors to provide low and controllable mechanical impedance. While these approaches provide certain benefits for control, their impact on system energy consumption is not widely understood. This paper presents a model for examining the energy consumption of drivetrains implementing various target dynamic behaviors in the presence of gear reductions and torque feedback. Analysis of this model reveals that under cyclical motions for many conditions, increasing the gear ratio results in greater energy loss. A similar model is presented for series elastic actuators and used to determine the energy consequences of various spring stiffness values. Both models enable the computation and optimization of power based on specific hardware manifestations, and illustrate how energy consumption sometimes defies conventional best-practices. Results of evaluating these two topologies as part of a drivetrain design optimization for two energy-efficient electrically driven humanoids are summarized. The model presented enables robot designers to predict the energy consequences of gearing and series elasticity for future robot designs, helping to avoid substantial energy sinks that may be inadvertently introduced if these issues are not properly analyzed.

Effect of compliance location in series elastic actuators

Robotica ◽  
2013 ◽  
Vol 31 (8) ◽  
pp. 1313-1318 ◽  
Author(s):  
Jonathon W. Sensinger ◽  
Lawrence E. Burkart ◽  
Gill A. Pratt ◽  
Richard F. ff. Weir
Keyword(s):  
Gear Ratio ◽  
Large Gear ◽  
Class 1 ◽  
In Series ◽  
Ratio Dependent ◽  
Series Elastic Actuators ◽  
Series Elastic ◽  
Instrumentation Design

SUMMARYSeries elastic actuators have beneficial properties for some robot applications. Several recent implementations contain alternative placements of the compliant element to improve instrumentation design. We use a class 1 versus class 2 lever model and energy-port methods to demonstrate in this paper that these alternative placements should still be classified as series elastic actuators. We also note that the compliance of proximal series elastic actuators is reflected by an augmented gear ratio dependent on the nominal gear ratio, which is significant for small gear ratios and approaches unity for large gear ratios. This reflected compliance is shown to differ depending on the sign of the gear ratio. We demonstrate that although the reflected compliance is only marginally influenced by the magnitude of the gear ratio, there are several notable differences, particularly for small gear ratios.

scholarly journals A General Framework for Minimizing Energy Consumption of Series Elastic Actuators With Regeneration

2017 ◽  
Author(s):  
Edgar Bolívar ◽  
Siavash Rezazadeh ◽  
Robert Gregg
Keyword(s):  
Energy Consumption ◽  
Elastic Element ◽  
Close Contact ◽  
Reference Trajectory ◽  
Ankle Motion ◽  
Natural Motion ◽  
Actuator Constraints ◽  
Natural Dynamics ◽  
Series Elastic Actuators ◽  
Series Elastic

The use of actuators with inherent compliance, such as series elastic actuators (SEAs), has become traditional for robotic systems working in close contact with humans. SEAs can reduce the energy consumption for a given task compared to rigid actuators, but this reduction is highly dependent on the design of the SEA’s elastic element. This design is often based on natural dynamics or a parameterized optimization, but both approaches have limitations. The natural dynamics approach cannot consider actuator constraints or arbitrary reference trajectories, and a parameterized elastic element can only be optimized within the given parameter space. In this work, we propose a solution to these limitations by formulating the design of the SEA’s elastic element as a non-parametric convex optimization problem, which yields a globally optimal conservative elastic element while respecting actuator constraints. Convexity is proven for the case of an arbitrary periodic reference trajectory with a SEA capable of energy regeneration. We discuss the optimization results for the tasks defined by the human ankle motion during level-ground walking and the natural motion of a single mass-spring system with a nonlinear spring. For all these tasks, the designed SEA reduces energy consumption and satisfies the actuator’s constraints.

Network Energy Consumption Models and Energy Efficient Algorithms

2012 ◽  
Vol 35 (3) ◽  
pp. 603-615 ◽  
Author(s):  
Fa ZHANG ◽  
Antonio Fernandez Anta ◽  
Lin WANG ◽  
Chen-Ying HOU ◽  
Zhi-Yong LIU
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Efficient Algorithms

Performance Analysis of Energy Efficient Opportunistic Routing Protocols in Wireless Sensor Network

2019 ◽  
Vol 09 ◽  
Author(s):  
Premkumar Chithaluru ◽  
Rajeev Tiwari ◽  
Kamal Kumar
Keyword(s):  
Energy Consumption ◽  
Routing Protocols ◽  
Energy Efficient ◽  
Data Communication ◽  
Opportunistic Routing ◽  
Link Quality ◽  
Delivery Ratio ◽  
Performance Parameters ◽  
Wireless Medium ◽  
Reduce Energy Consumption

Background: Energy Efficient wireless routing has been an area of research particularly to mitigate challenges surrounding performance in category of Wireless Networks. Objectives: The Opportunistic Routing (OR) technique was explored in recent times and exhibits benefits over many existing protocols and can significantly reduce energy consumption during data communication with very limited compromise on performance. Methods : Using broadcasting nature of the wireless medium, OR practices to discourse two foremost issues of variable link quality and unpredictable node agility in constrained WSNs. OR has a potential to reduce delay in order to increase the consistency of data delivery in network. Results : Various OR based routing protocols have shown varying performances. In this paper, a detailed conceptual and experimental analysis is carried out on different protocols that uses OR technique for providing more clear and definitive view on performance parameters like Message Success Rate, Packet Delivery Ratio and Energy Consumption.

A Split Network based Routing Approach in Wireless Sensor Network to Enhance Network Stability

2019 ◽  
Vol 9 (4) ◽  
pp. 480-487 ◽  
Author(s):  
Hardeep S. Saini ◽  
Dinesh Arora
Keyword(s):  
Energy Consumption ◽  
Sensor Network ◽  
Energy Efficient ◽  
Cluster Head ◽  
Base Station ◽  
Operating Efficiency ◽  
Network Stability ◽  
Major Factors ◽  
Ch Selection

Background & Objective: The operating efficiency of a sensor network totally relies upon the energy that is consumed by the nodes to perform various tasks like data transmission etc. Thus, it becomes mandatory to consume the energy in an intelligent way so that the network can run for a long period. This paper proposed an energy efficient Cluster Head (CH) selection mechanism by considering the distance to Base Station (BS), distance to node and energy as major factors. The concept of volunteer node is also introduced with an objective to reduce the energy consumption of the CH to transmit data from source to BS. The role of the volunteer node is to transmit the data successfully from source to destination or BS. Conclusion: The results are observed with respect to the Alive nodes, dead nodes and energy consumption of the network. The outcome of the proposed work proves that it outperforms the traditional mechanisms.

Sign in / Sign up

Export Citation Format

Share Document