In-Hand Manipulation Primitives for a Minimal, Underactuated Gripper With Active Surfaces

2016 ◽  
Author(s):  
Raymond R. Ma ◽  
Aaron M. Dollar
Keyword(s):  
A Priori ◽  
Open Loop ◽  
Object Motion ◽  
A Priori Knowledge ◽  
Open Loop Control ◽  
Loop Control ◽  
Grasp Stability ◽  
Control Schemes ◽  
And Control ◽  
Underactuated Finger

Dexterous in-hand manipulation tasks have been difficult to execute, even with highly complex hands and control schemes, as the object grasp stability needs to be maintained while it is displaced in the hand workspace. Researchers have shown that underactuated, adaptive hand designs can effectively immobilize objects with simple, open-loop, but there have been few cases where underactuation has been leveraged to enhance in-hand manipulation. In this work, we investigate the performance of a gripper utilizing a thumb with an active, belt-driven, conveyor surface and an opposing, underactuated finger with passive rollers, for a variety of manipulation tasks and range of objects. We show that consistent, repeatable object motion can be obtained while ensuring a rigid grasp without a priori knowledge of the object geometry or contact locations, due to the adaptive qualities of underactuated design. Many dexterous in-hand manipulation examples with their anthropomorphic equivalents are examined, and simple, open-loop control schemes to optimize the repeatability of these tasks are proposed.

Simulation and Control of a Commercial Double Effect Evaporator: Tomato Juice

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Praveen Yadav ◽  
Amiya K Jana
Keyword(s):  
Double Effect ◽  
Open Loop ◽  
Simulation Experiments ◽  
Loop Control ◽  
Process Dynamics ◽  
Point Tracking ◽  
Tomato Paste ◽  
Control Schemes ◽  
And Control ◽  
Gain Scheduled

This work aims to present a detailed study on a commercial double-effect tomato paste evaporation system. The modeling equations formulated for process simulation belong to backward feeding arrangement. Open-loop process dynamics has been studied by rigorous simulation of the model structure. In the next, three multi-loop control schemes, namely conventional proportional integral (PI), gain-scheduled PI (GSPI) and nonlinear PI (NLPI), have been synthesized for the sample process. Finally, several simulation experiments have been conducted to investigate the comparative closed-loop performance based on set point tracking and disturbance rejection.

scholarly journals Model-based Control Strategies for Anaerobic Digestion Processes

BIOMATH ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 1907127 ◽  
Author(s):  
Neli Dimitrova ◽  
Mikhail Krastanov
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Control Strategies ◽  
A Priori ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Model Based Control ◽  
Anaerobic Wastewater Treatment

In this paper we consider a four-dimensional bioreactor model, describing an anaerobic wastewater treatment with methane production. Different control strategies for stabilizing the dynamics are presented and discussed. A general and practice-oriented bounded open-loop control is proposed, aimed to steer the model solutions towards an a priori given set in thephase plane.

scholarly journals Active Control of Dynamic Platforms

2005 ◽  
Vol 219 (8) ◽  
pp. 551-563
Author(s):  
K Rieger ◽  
K Bouazza-Marouf
Keyword(s):  
Vertical Motion ◽  
Weather Conditions ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Control Schemes ◽  
Platform System ◽  
Experimental Rig

The control of a dynamic platform system for offshore operations in adverse weather conditions is discussed in this paper. The aim is to control the deck of the dynamic platform system to remain stationary irrespective of displacement-type base disturbances and force/ torque-type deck disturbances. Two control schemes based on the principle of invariance are described. Open-loop control, with drift cancellation, is implemented for the heave (vertical) motion, which is not always possible to obtain in practical systems. An experimental rig has been used to investigate and validate simulation results. Good simulation and experimental results have been obtained.

Minimum-Time Eigenaxis Rotation Maneuvers for a Spacecraft With Three Axis Reaction Wheels

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Haoyu Wang ◽  
Guowei Zhao ◽  
Hai Huang
Keyword(s):  
Numerical Simulation ◽  
Momentum Conservation ◽  
Open Loop ◽  
Minimum Time ◽  
Control Law ◽  
Open Loop Control ◽  
Model Uncertainties ◽  
Loop Control ◽  
Control Scheme ◽  
And Control

This paper proposes a planning method of the theoretically fastest slew path, and correspondingly, an analytical open-loop control law for the minimum-time eigenaxis rotation of spacecraft with three reaction wheels. The path planning and the control law are based on the angular momentum conservation of the spacecraft system. Then, a control scheme is also proposed to correct the maneuver error caused by model uncertainties. The control law and control scheme are verified in numerical simulation cases. The results show that the control law would realize the fastest slew path for an eigenaxis rotation, and the control scheme is feasible in shortening the slew time.

Simulation Research on One-Cycle Controlled AC-AC Cuk Converter

2013 ◽  
Vol 710 ◽  
pp. 501-505
Author(s):  
Chun Jie Wang ◽  
Peng Fei Yu
Keyword(s):  
Control Method ◽  
Input Voltage ◽  
Transmission Efficiency ◽  
Open Loop ◽  
Open Loop Control ◽  
Simulation Research ◽  
Loop Control ◽  
Cuk Converter ◽  
Excellent Control ◽  
And Control

AC-AC Cuk Converter which constituted by bidirectional switch has an advantage of high transmission efficiency, but most of them usually use open-loop control. In this paper, we propose one-cycle control of the AC-AC Cuk converter. The operating principle and control method are presented. The simulation results based on Matlab are given to verify its rationality and feasibility. Compared to common PID control, it has excellent control performance. Furthermore, one-cycle controlled AC-AC Cuk converter has the ability to reject input voltage perturbations and faster dynamic response.

Open-loop control of compensation for optical propagation through a turbulent shear flow

1998 ◽  
Author(s):  
C. Truman ◽  
Lenore McMackin ◽  
Robert Pierson ◽  
Kenneth Bishop ◽  
Ellen Chen
Keyword(s):  
Shear Flow ◽  
Open Loop ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Open Loop Control ◽  
Loop Control ◽  
Optical Propagation

Precise open-loop control of MEMS deformable mirror shape

2008 ◽  
Author(s):  
Thomas Bifano ◽  
Jason Stewart ◽  
Alioune Diouf
Keyword(s):  
Open Loop ◽  
Deformable Mirror ◽  
Open Loop Control ◽  
Loop Control

Active Control of Combustion Instability Using Symmetric and Asymmetric Premix Fuel Modulation

2007 ◽  
Author(s):  
Daniel Guyot ◽  
Christian Oliver Paschereit
Keyword(s):  
Heat Release ◽  
Closed Loop ◽  
Modulation Frequency ◽  
Combustion Instability ◽  
Open Loop ◽  
Closed Loop Control ◽  
Nox Emissions ◽  
Loop Control ◽  
Asymmetric Modulation ◽  
Control Schemes

Active instability control was applied to an atmospheric swirl-stabilized premixed combustor using open loop and closed loop control schemes. Actuation was realised by two on-off valves allowing for symmetric and asymmetric modulation of the premix fuel flow while maintaining constant time averaged overall fuel mass flow. Pressure and heat release fluctuations in the combustor as well as NOx, CO and CO2 emissions in the exhaust were recorded. In the open loop circuit the heat release response of the flame was first investigated during stable combustion. For symmetric fuel modulation the dominant frequency in the heat release response was the modulation frequency, while for asymmetric modulation it was its first harmonic. In stable open loop control a reduction of NOx emissions due to fuel modulation of up to 19% was recorded. In the closed loop mode phase-shift control was applied while triggering the valves at the dominant oscillation frequency as well as at its second subharmonic. Both, open and closed loop control schemes were able to successfully control a low-frequency combustion instability, while showing only a small increase in NOx emissions compared to, for example, secondary fuel modulation. Using premixed open loop fuel modulation, attenuation was best when modulating the fuel at frequencies different from the dominant instability frequency and its subharmonic. The performance of asymmetric fuel modulation was generally slightly better than for symmetric modulation in terms of suppression levels as well as emissions. Suppression of the instability’s pressure rms level of up to 15.7 dB was recorded.

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