Energy-Efficient Servo Control of Pneumatic Systems via Direct Cross Flow

2006 ◽  
Author(s):  
Xiangrong Shen ◽  
Michael Goldfarb
Keyword(s):  
Energy Saving ◽  
Mass Flow ◽  
Energy Savings ◽  
Sliding Mode ◽  
Cross Flow ◽  
Servo Control ◽  
Control Approach ◽  
Direct Cross ◽  
Pneumatic Servo System ◽  
Spool Valve

This paper proposes a structure and control approach for the energy saving servo control of a pneumatic servo system. The energy saving approach is enabled by supplementing a standard four-way spool valve controlled pneumatic actuator with an additional two-way valve that enables flow between the cylinder chambers. The "crossflow" valve enables recirculation of pressurized air, and thus enables the extraction of stored energy that would otherwise be exhausted to atmosphere. A control approach is formulated that supplements, to the extent possible, the mass flow required by a sliding mode controller with the recirculated mass flow provided by the crossflow valve. Following the control formulation, experimental results are presented that indicate energy savings of 25% to 52%, with essentially no compromise in tracking performance relative to the standard sliding mode control approach (i.e., relative to control via a standard four-way spool valve, without the supplemental flow provided by the crossflow valve).

Energy Saving in Pneumatic Servo Control Utilizing Interchamber Cross-Flow

2006 ◽  
Vol 129 (3) ◽  
pp. 303-310 ◽  
Author(s):  
Xiangrong Shen ◽  
Michael Goldfarb
Keyword(s):  
Energy Saving ◽  
Mass Flow ◽  
Energy Savings ◽  
Sliding Mode ◽  
Cross Flow ◽  
Servo Control ◽  
Control Approach ◽  
Pneumatic Servo System ◽  
And Control ◽  
Spool Valve

This paper proposes a structure and control approach for the energy saving servo control of a pneumatic servo system. The energy saving approach is enabled by supplementing a standard four-way spool valve controlled pneumatic actuator with an additional two-way valve that enables flow between the cylinder chambers. The “crossflow” valve enables recirculation of pressurized air, and thus enables the extraction of stored energy that would otherwise be exhausted to the atmosphere. A control approach is formulated that supplements, to the extent possible, the mass flow required by a sliding mode controller with the recirculated mass flow provided by the crossflow valve. Following the control formulation, experimental results are presented that indicate energy savings of 25–52%, with essentially no compromise in tracking performance relative to the standard sliding mode control approach (i.e., relative to control via a standard four-way spool valve, without the supplemental flow provided by the crossflow valve).

Dynamic Constraint-Based Energy-Saving Control of Pneumatic Servo Systems

2005 ◽  
Vol 128 (3) ◽  
pp. 655-662 ◽  
Author(s):  
Khalid A. Al-Dakkan ◽  
Eric J. Barth ◽  
Michael Goldfarb
Keyword(s):  
Energy Saving ◽  
Degrees Of Freedom ◽  
Energy Savings ◽  
Sliding Mode ◽  
Servo Systems ◽  
Control Approach ◽  
Dynamic Constraint ◽  
Energy Saving Control ◽  
Control Methodology ◽  
Spool Valve

This paper proposes a control approach that can provide significant energy savings for the control of pneumatic servo systems. The control methodology is formulated by decoupling the standard four-way spool valve used for pneumatic servo control into two three-way valves, then using the resulting two control degrees of freedom to simultaneously satisfy a performance constraint (which for this paper is based on the sliding mode sliding condition), and an energy-saving dynamic constraint that minimizes cylinder pressures. The control formulation is presented, followed by experimental results that indicate significant energy savings with essentially no compromise in tracking performance relative to control with a standard four-way spool valve.

A Multi-Objective Sliding Mode Approach for the Energy Saving Control of Pneumatic Servo Systems

2003 ◽  
Author(s):  
Khalid A. Al-Dakkan ◽  
Eric J. Barth ◽  
Michael Goldfarb
Keyword(s):  
Energy Saving ◽  
Degrees Of Freedom ◽  
Energy Savings ◽  
Sliding Mode ◽  
Experimental Results ◽  
Servo Systems ◽  
Control Approach ◽  
Servo Actuator ◽  
Actuator Control ◽  
Spool Valve

This paper proposes a variation on a sliding mode control approach that provides significant energy savings for the control of pneumatic servo systems. The control methodology is formulated by first decoupling the standard four-way spool valve used for pneumatic servo control into two three-way valves, then using the resulting two control degrees of freedom to simultaneously satisfy both the sliding mode sliding condition and a dynamic constraint that minimizes airflow. The control formulation is presented, followed by experimental results that indicate significant energetic savings with essentially no compromise in tracking performance relative to a standard four-way spool valve approach. Specifically, relative to standard four-way spool valve pneumatic servo actuator control, the experimental results indicate energy saving of 27 to 45%, depending on the desired tracking frequency.

Study and Application of a Slide Mode Control on Pneumatic Force Servo System

2012 ◽  
Vol 466-467 ◽  
pp. 896-900
Author(s):  
Yan Li Yang ◽  
Wei Xiang Shi ◽  
Yan Cao ◽  
Lei Lei
Keyword(s):  
Pid Control ◽  
Sliding Mode ◽  
Servo System ◽  
Servo Control ◽  
Time Varying ◽  
Slide Mode Control ◽  
Control Approach ◽  
Mode Control ◽  
Servo Control System ◽  
Identification Approach

In this paper, a sliding mode control approach combined with the boundary saturation function approach is put forward and used in a pneumatic force servo system to achieve an exact force control. First, a comparatively accurate model of the system is obtained by using the system identification approach and an analysis is made on the time-varying nature of the model. Then, it is designed by use of the boundary saturation approach, thus overcoming the system instability caused by the non-linearity of the proportional pressure valve and the change of the temperature inside the air cylinder. Finally, the performance of the pneumatic force servo control system is simulated and a comparison is made with the PID control. Results show the feasibility and effectiveness of the approach.

scholarly journals Finite-Time Composite Position Control for a Disturbed Pneumatic Servo System

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaojun Wang ◽  
Jiankun Sun ◽  
Guipu Li
Keyword(s):  
Finite Time ◽  
State Feedback ◽  
Position Control ◽  
Sliding Mode ◽  
State Feedback Control ◽  
Servo Systems ◽  
Control Approach ◽  
Composite Control ◽  
Control Scheme ◽  
Pneumatic Servo System

This paper investigates the finite-time position tracking control problem of pneumatic servo systems subject to hard nonlinearities and various disturbances. A finite-time disturbance observer is firstly designed, which guarantees that the disturbances can be accurately estimated in a finite time. Then, by combining disturbances compensation and state feedback controller together, a nonsmooth composite controller is developed based on sliding mode control approach and homogeneous theory. It is proved that the tracking errors under the proposed composite control approach can be stabilized to zero in finite time. Moreover, compared with pure state feedback control, the proposed composite control scheme offers a faster convergence rate and a better disturbance rejection property. Finally, numerical simulations illustrate the effectiveness of the proposed control scheme.

scholarly journals Energy Saving and Charging Discharging Characteristics of Multiple PCMs Subjected to Internal Air Flow

Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 275
Author(s):  
Ahmed J. Hamad
Keyword(s):  
Phase Change ◽  
Energy Saving ◽  
Air Temperature ◽  
Temperature Control ◽  
Phase Change Materials ◽  
Energy Savings ◽  
Heating System ◽  
Air Heating ◽  
Room Model ◽  
Model Temperature

One essential utilization of phase change materials as energy storage materials is energy saving and temperature control in air conditioning and indirect solar air drying systems. This study presents an experimental investigation evaluating the characteristics and energy savings of multiple phase change materials subjected to internal flow in an air heating system during charging and discharging cycles. The experimental tests were conducted using a test rig consisting of two main parts, an air supply duct and a room model equipped with phase change materials (PCMs) placed in rectangular aluminum panels. Analysis of the results was based on three test cases: PCM1 (Paraffin wax) placed in the air duct was used alone in the first case; PCM2 (RT–42) placed in the room model was used alone in the second case; and in the third case, the two PCMs (PCM1 and PCM2) were used at the same time. The results revealed a significant improvement in the energy savings and room model temperature control for the air heating system incorporated with multiple PCMs compared with that of a single PCM. Complete melting during the charging cycle occurred at temperatures in the range of 57–60 °C for PCM1 and 38–43 °C for PCM2, respectively, thereby validating the reported PCMs’ melting–solidification results. Multiple PCMs maintained the room air temperature at the desired range of 35–45.2 °C in the air heating applications by minimizing the air temperature fluctuations. The augmentation in discharging time and improvement in the room model temperature using multiple PCMs were about 28.4% higher than those without the use of PCMs. The total energy saving using two PCMs was higher by about 29.5% and 46.7% compared with the use of PCM1 and PCM2, respectively. It can be concluded that multiple PCMs have revealed higher energy savings and thermal stability for the air heating system considered in the current study.

Evaluation methods of the daylight performance and potential energy saving of tubular daylight guide systems: A review

2021 ◽  
pp. 1420326X2199241
Author(s):  
Hanlin Li ◽  
Dan Wu ◽  
Yanping Yuan ◽  
Lijun Zuo
Keyword(s):  
Potential Energy ◽  
Energy Saving ◽  
Energy Savings ◽  
Performance Metrics ◽  
Field Measurements ◽  
Building Design ◽  
Estimation Methods ◽  
The Past ◽  
Potential Energy Saving ◽  
Daylight Performance

In the past 30 years, tubular daylight guide systems (TDGSs) have become one of the most popular ways to transport outdoor natural light into the inner space in building design. However, tubular daylight guide systems are not widely used because of the lack of methods to evaluate methods on the suitability of the TDGSs. This study therefore summarizes the daylight performance metrics of TDGSs and presents the estimation methods in terms of field measurements, simulation and empirical formulae. This study focuses on the daylight performance and potential energy savings of TDGSs. Moreover, this study will be helpful for building designers to build healthy, comfortable and energy-saving indoor environment.

Constraint-following servo control for an underactuated mobile robot under hard constraints

2021 ◽  
pp. 095965182110248
Author(s):  
Duo Fu ◽  
Jin Huang ◽  
Wen-Bin Shangguan ◽  
Hui Yin
Keyword(s):  
Mobile Robot ◽  
Control Problem ◽  
Servo Control ◽  
Robot Motion ◽  
Soft Constraints ◽  
Rigorous Proof ◽  
Control Approach ◽  
Hard Constraints

This article formulates the control problem of underactuated mobile robot as servo constraint-following, and develops a novel constraint-following servo control approach for underactuated mobile robot under both servo soft and hard constraints. Servo soft constraints are expressed as equalities, which may be holonomic or non-holonomic. Servo hard constraints are expressed as inequalities. It is required that the underactuated mobile robot motion eventually converges to servo soft constraints, and satisfies servo hard constraints at all times. Diffeomorphism is employed to incorporate hard constraints into soft constraints, yielding new soft constraints to relax hard constraints. By this, we design a constraint-following servo control based on the new servo soft constraints, which drives the system to strictly follow the original servo soft and hard constraints. The effectiveness of the proposed approach is proved by rigorous proof and simulations.

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