Maximum Peak-Gain Margin 2DOF-IMC Tuning for a 2DOF-PID Filter Set Point Controller Under Parametric Uncertainty

The specification of controller setting for a standard controller typically requires a trade-off between set point tracking and disturbance rejection. For this reason two simple strategies can be used to adjust the set point and disturbance responses independently. These strategies are referred to as controllers with two degree of freedom. Unfortunately, the tuning parameters in the case of model uncertainty at two degree of freedom structure controller is difficult to obtain. Juwari et al (2013) has introduced maximum peak-gain margin (Mp-GM) tuning method to obtain setting parameter of two degree of freedom structure controller based on model uncertainty. This tuning method are able to obtain the good controller parameter even under processes uncertainties on standard two degree of freedom (was abbreviated as 2DOF) IMC. This research will be conducted on development maximum peak-gain margin tuning method for a two degree of freedom PID filter set point structure controller. The simulation results show that the maximum peak gain margin tuning method can give a good target set point tracking, disturbance rejection and robustness in system a 2DOF-PID filter set point controller

The Penn Jerboa: A Platform for Exploring Parallel Composition of Templates

We have built a 12DOF, passive-compliant legged, tailed biped actuated by four brushless DC motors. We anticipate that this machine will achieve varied modes of quasistatic and dynamic balance, enabling a broad range of locomotion tasks including sitting, standing, walking, hopping, running, turning, leaping, and more. Achieving this diversity of behavior with a single under-actuated body, requires a correspondingly diverse array of controllers, motivating our interest in compositional techniques that promote mixing and reuse of a relatively few base constituents to achieve a combinatorially growing array of available choices. Here we report on the development of one important example of such a behavioral programming method, the construction of a novel monopedal sagittal plane hopping gait through parallel composition of four decoupled 1DOF base controllers. For this example behavior, the legs are locked in phase and the body is fastened to a boom to restrict motion to the sagittal plane. The platform's locomotion is powered by the hip motor that adjusts leg touchdown angle in flight and balance in stance, along with a tail motor that adjusts body shape in flight and drives energy into the passive leg shank spring during stance. The motor control signals arise from the application in parallel of four simple, completely decoupled 1DOF feedback laws that provably stabilize in isolation four corresponding 1DOF abstract reference plants. Each of these abstract 1DOF closed loop dynamics represents some simple but crucial specific component of the locomotion task at hand. We present a partial proof of correctness for this parallel composition of template reference systems along with data from the physical platform suggesting these templates are anchored as evidenced by the correspondence of their characteristic motions with a suitably transformed image of traces from the physical platform.Comment: Technical Report to Accompany: A. De and D. Koditschek, "Parallel composition of templates for tail-energized planar hopping," in 2015 IEEE International Conference on Robotics and Automation (ICRA), May 2015. v2: Used plain latex article, correct gap radius and specific force/torque number

Hackable Instruments: Supporting Appropriation and Modification in Digital Musical Interaction

This paper investigates the appropriation of digital musical instruments, wherein the performer develops a personal working relationship with an instrument that may differ from the designer's intent. Two studies are presented which explore different facets of appropriation. First, a highly restrictive instrument was designed to assess the effects of constraint on unexpected creative use. Second, a digital instrument was created which initially shared several constraints and interaction modalities with the first instrument, but which could be rewired by the performer to discover sounds not directly anticipated by the designers. Each instrument was studied with 10 musicians working individually to prepare public performances on the instrument. The results suggest that constrained musical interactions can promote the discovery of unusual and idiosyncratic playing techniques, and that tighter constraints may paradoxically lead to a richer performer experience. The diversity of ways in which the rewirable instrument was modified and used indicates that its design is open to interpretation by the performer, who may discover interaction modalities that were not anticipated by the designers

Two degree of freedom fractional PI scheme for automatic voltage regulation

The effectiveness of the inferential control scheme based on robust fractional-order proportional integral (FOPI) controller is presented for automatic voltage regulation (AVR) applications. The method uses two degree of freedom (2DOF) in FOPI scheme, which is tuned with the whale optimization algorithm (WOA). Actually, any AVR needs to keep the reactive power of synchronous generator at demand level, stable voltage and frequency of the electrical power supplies. In this study, the 2DOF FOPI controller is proposed to deviate away from the standard integer order, to show the superiority of extra degree of freedom in both structure and controller. To improve the AVR performance, a new performance measure is proposed for the parameter tuning. The method acquires the significant robustness in parameter perturbation and disturbance interruptions. It is observed in the step response quality that the overshoot and settling time can be reduced to approximately by half than the recently published scheme. The various analyses are shown to accept the dominance of the proposed controller in terms of robustness

A Two-Degree-Of-Freedom Time-Optimal Solution for Hard Disk Drive Servo Problems

This paper deals with the hard disk drive (HDD) servo problems. A novel discrete time-optimal control solution is proposed in a two-degree-of-freedom (2DOF) structure, employing both the feedback and feedforward controllers. The time-optimal feedback controller, derived from a simple, double integral plant model, shows remarkable robustness and disturbance rejection in the presence of resonant modes, measurement noises and position and torque disturbances. It eliminates the needs for two separate controllers for track-seeking and track-following operations. The proposed feedforward controller in this 2DOF structure proves to be quite beneficial in reducing the seek time. It also allows the feedback controller to be tuned more aggressively, which helps to improve the quality of track following. The proposed control scheme offers a novel basic control structure for HDD servo, upon which numerous further improvements can be made. It is successfully tested in simulation on an industrial 13.0-kTPI HDD

Parallel Control Structure Scheme for Load Frequency Controller Design using Direct Synthesis Approach

This paper presents load frequency controller design for a single area as well as the multi-area thermal power system using direct synthesis approach with parallel control structure (PCS) scheme. The set-point and load frequency controller has been designed for frequency regulation and maintains tie-line power within a pre-specified limit for LFC power system.  The proposed controller has been implemented for single-area, two-area, and four-area thermal power system for frequency regulation. The proposed method shows impressive simulation results compared with existed control method. The robustness of the proposed method has been examined with the help maximum sensitivity and parametric variation in the nominal power system