Combination of the Flow Disturbance Observer and Base Plate Jerk Feedback in a Pneumatic Positioning Stage

2013

JAMDSM

Self Cite

In this paper, a unidirectional positioning stage which is supported by four coil-type spring isolators and actuated by four pneumatic cylinders is considered. The stage jerk feedback scheme (SJFB) with positive polarity is proposed to reduce the stage mass, resulting in the improvement of positioning speed. However, reduction of stage mass results in the overshoot that can be controlled by increasing the stage stiffness through the outer feedback loop controller. In addition, to avoid the selfoscillation of stage caused by high gain of SJFB and to improve the repeatability, the conventionally used scheme, namely, base plate jerk feedback (BPJFB) with positive polarity based on its damping role is combined with the SJFB scheme. It is concluded from the experimental results that the proposed control system obeys the related theory and provides high speed positioning with improved repeatability. The amount of the reduced mass through SJFB scheme is also experimentally estimated.

Section: Introductionmentioning

confidence: 84%

Section: Proposed Control Block Diagram and Related Theorymentioning

confidence: 99%

Section: Proposed Control Block Diagram and Related Theorymentioning

confidence: 99%

“…The parameters shown in Table 1 were kept fixed during the experiments with the same values as tuned in Ref. (9). The experiments were performed through the following steps:…”

Section: Experimental Strategymentioning

confidence: 99%

See 2 more Smart Citations

Positive Stage Jerk Feedback Combined with Positive Base Plate Jerk Feedback to Improve the Positioning Speed of a Pneumatic Stage

Wali

2013

JAMDSM

Self Cite

“…As a control method of pneumatic actuators, proportional-derivative-double derivative (PDD 2 ) control (Kagawa, et al, 2000) is known. In our previous work (Wali and Wakui, 2012), we utilized this control scheme for the positioning of the pneumatic stage. The advantage of the PDD 2 control is that, by adjusting parameters of a PDD 2 controller, the desired damping and stiffness of a control system can be easily obtained.…”

Section: Introductionmentioning

confidence: 99%

Positioning control of a pneumatic stage under different pipe length: Performance improvement of PDD<sup>2</sup> control and suppression of flow disturbance

Ito

Nakamura

2015

JAMDSM

Self Cite

In this study, we consider the positioning of a pneumatic stage in order to compensate effects of different length of pipes, which connect servo valves and cylinders. Since, in industrial scenes, it is difficult to use pipes of the same length due to the structure of industries, the length of each pipe is often different. In this case, the characteristic of the pneumatic system, which consists of the pipes, servo valves, and chambers, changes in accordance with the pipe length. It leads to two issues: The first one is that the performance of proportional-derivative-double derivative (PDD 2 ) control, which is effective for the control of pneumatic actuators, is degraded. To overcome this issue, the parameter of a pre-compensator for the PDD 2 control is tuned. The suitable value of this tuned parameter increases with the length of the pipes. The second one is that the effects of flow disturbance increase due to the different pipe length. When the length of the pipes is not same, it is probable that the magnitude of flow disturbance transmitted to each pipe is different. For this reason, multiple flow disturbance observers (FDOBs) are implemented in a control system. Experimental results show that the repeatability of the positioning is improved by using the FDOBs.

Combining the positive stage and base plate jerk feedback schemes to speedup a pneumatic stage

Wali

IECON 2013 - 39th Annual Conference of the IEEE Industrial Electronics Society

2013

Self Cite

In this paper, the stage jerk feedback (SJFB) with positive polarity is proposed to reduce the stage mass in a pneumatically actuated positioning system. Reduction of stage mass, from one side, results in the high speed positioning which is the main objective of this study. However, on the other hand, it results in an overshoot in the positioning response, which can be compensated through the stiffness gain of the outer loop controller. Moreover, the system becomes easily unstable by further increasing the SJFB gain due to the positive polarity of this controller. This issue is solved by coupling the conventional controller, namely, the base plate jerk feedback (BPJFB) scheme with positive polarity. The experimental results show the effectiveness of both schemes. In addition, based on the experimental estimation, the SJFB has a significant role on the stage mass reduction.