scholarly journals A Comparison between Two Force-Position Controllers with Gravity Compensation Simulated on a Humanoid Arm

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Giovanni Gerardo Muscolo ◽  
Kenji Hashimoto ◽  
Atsuo Takanishi ◽  
Paolo Dario

The authors propose a comparison between two force-position controllers with gravity compensation simulated on the DEXTER bioinspired robotic arm. The two controllers are both constituted by an internal proportional-derivative (PD) closed-loop for the position control. The force control of the two systems is composed of an external proportional (P) closed-loop for one system (P system) and an external proportional-integrative (PI) closed-loop for the other system (PI system). The simulation tests performed with the two systems on a planar representation of the DEXTER, an eight-DOF bioinspired arm, showed that by varying the stiffness of the environment, with a correct setting of parameters, both systems ensure the achievement of the desired force regime and with great precision the desired position. The two controllers do not have large differences in performance when interacting with a lower stiffness environment. In case of an environment with greater rigidity, the PI system is more stable. The subsequent implementation of these control systems on the DEXTER robotic bioinspired arm gives guidance on the design and control optimisation of the arms of the humanoid robot named SABIAN.

2013 ◽  
Vol 461 ◽  
pp. 352-357
Author(s):  
Hua Ming Wang ◽  
Hua An Luo ◽  
Bin Yang

Dielectric Electroactive Polymers (EAPs) are closest to natural muscles in terms of strain, energy density, efficiency and speed. A 2-DOF (Degree of Freedom) rotary manipulator driven by soft dielectric EAP is designed based on the biological agonist–antagonist configuration. Compact rolled actuators are chosen and implemented to drive the manipulator. To avoid the complicated solving of nonlinear differential equations, electromechanical characteristics of actuators are obtained by measuring their force behavior under different voltages and lengths. A CMAC (Cerebellar model articulation controller) neural network-based closed loop controller is developed to implement the position control of the manipulator and is evaluated by tracking a circle. According to the force analysis of the manipulator, forces of antagonistic actuators are determined by force decomposition to produce the desired force output, and then the voltages for actuators at certain lengths can be calculated through measured electromechanical characteristics. Experiment shows the measured force agrees well with the desired force. Due to the advantages of dielectric EAP, the manipulator has application prospects in areas of rehabilitation, force feedback or flexible manipulation without damage.


Author(s):  
Thilo von Pape

This chapter discusses how autonomous vehicles (AVs) may interact with our evolving mobility system and what they mean for mobile communication research. It juxtaposes a conceptualization of AVs as manifestations of automation and artificial intelligence with an analysis of our mobility system as a historically grown hybrid of communication and transportation technologies. Since the emergence of railroad and telegraph, this system has evolved on two layers: an underlying infrastructure to power and coordinate the movements of objects, people, and ideas in industrially scaled speeds, volumes, and complexity and an interface to seamlessly access this infrastructure and control it. AVs are poised to further enhance the seamlessness which mobile phones and cars already lent to mobility. But in assuming increasingly sophisticated control tasks, AVs also disrupt an established shift toward individual control, demanding new interfaces to enable higher levels of individual and collective control over the mobility infrastructure.


Robotica ◽  
2020 ◽  
pp. 1-18
Author(s):  
M. Garcia ◽  
P. Castillo ◽  
E. Campos ◽  
R. Lozano

SUMMARY A novel underwater vehicle configuration with an operating principle as the Sepiida animal is presented and developed in this paper. The mathematical equations describing the movements of the vehicle are obtained using the Newton–Euler approach. An analysis of the dynamic model is done for control purposes. A prototype and its embedded system are developed for validating analytically and experimentally the proposed mathematical representation. A real-time characterization of one mass is done to relate the pitch angle with the radio of displacement of the mass. In addition, first validation of the closed-loop system is done using a linear controller.


Author(s):  
L. Viktor Larsson ◽  
Robert Lejonberg ◽  
Liselott Ericson

When electrifying working machines, energy-efficient operation is key to maximise the use of the limited capacity of on-board batteries. Previous research indicate high energy savings by means of component and system design. In contrast, this paper focuses on how to maximise energy efficiency by means of both design and control optimisation. Simulation-based optimisation and dynamic programming are used to find the optimal electric motor speed trajectory and component sizes for a scooptram machine equipped with pump control, enabled by digital displacement pumps with dynamic flow sharing. The results show that a hardware configuration and control strategy that enable low pump speed minimise drag losses from parasitic components, partly facilitated by the relatively high and operation point-independent efficiencies of the pumps and electric motor. 5–10% cycle energy reductions are indicated, where the higher figure was obtained for simultaneous design and control optimisation. For other, more hydraulic-intense applications, such as excavators, greater reductions could be expected.


Author(s):  
Karl Uebel ◽  
Henrique Raduenz ◽  
Petter Krus ◽  
Victor Juliano de Negri

This paper deals with design optimisation of hydraulic hybrid drivelines during early concept design phases. To set the design parameters of a hybrid driveline such as gear ratios, pump/motor displacements and size of energy storage, the energy management of the hybrid machine needs to be considered as well. This is problematic since a nested design and control optimisation normally requires substantial computer power and is time-consuming. Few previous studies have treated combined design and control optimisation of hydraulic hybrid vehicles using detailed, non-linear component driveline models. Furthermore, previously proposed design optimisation methods for on-road vehicles are not suitable for heavy off-road machines operating in short repetitive cycles with high transient power output. The paper demonstrates and compares different optimisation approaches for design and control optimisation combining deterministic dynamic programming and non-gradient based numerical optimisation. The results show that a simple rule-based energy management strategy can be sufficient to find the optimal hardware design even though non-optimal control laws are used.


2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Yanxiang Shi

Two types of coronary artery system N-type and S-type, are investigated. The threshold conditions for the occurrence of Smale horseshoe chaos are obtained by using Melnikov method. Numerical simulations including phase portraits, potential diagram, homoclinic bifurcation curve diagrams, bifurcation diagrams, and Poincaré maps not only prove the correctness of theoretical analysis but also show the interesting bifurcation diagrams and the more new complex dynamical behaviors. Numerical simulations are used to investigate the nonlinear dynamical characteristics and complexity of the two systems, revealing bifurcation forms and the road leading to chaotic motion. Finally the chaotic states of the two systems are effectively controlled by two control methods: variable feedback control and coupled feedback control.


Author(s):  
E. Georgiou ◽  
J. Dai

The motivation for this work is to develop a platform for a self-localization device. Such a platform has many applications for the autonomous maneuverable non-holonomic mobile robot classification, which can be used for search and rescue or for inspection devices where the robot has a desired path to follow but because of an unknown terrain, the device requires the ability to make ad-hoc corrections to its movement to reach its desire path. The mobile robot is modeled using Lagrangian d’Alembert’s principle considering all the possible inertias and forces generated, and are controlled by restraining movement based on the holonomic and non-holonomic constraints of the modeled vehicle. The device is controlled by a PD controller based on the vehicle’s holonomic and non-holonomic constraints. An experiment was setup to verify the modeling and control structure’s functionality and the initial results are promising.


2014 ◽  
Vol 596 ◽  
pp. 620-624
Author(s):  
Yan Bo Hui ◽  
Yong Gang Wang ◽  
Li Wang ◽  
Qun Feng Niu

According to auto-incasing equipment characteristic and control demand, a kind of salt in-bags incasing control management system was designed. The paper introduced the key technologies realization of the system. In the paper, a new fuzzy controller was designed to build a dual closed-loop fuzzy control system, realizing incasing goal site error on-line continuous correction. A logistics management module based on e-Tag was designed to realize product information traceable management. The experimental results show the system realizes accurate position control and RFID logistics management with high reliability and high control precision. The system can be popularized to other products packaging industry.


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