Rosbi Mamat

Impact of Ambulance Dispatch Policies on Performance of Emergency Medical Services

In ambulance location models, fleet size and ambulance location sites are two critical factors that emergency medical service (EMS) managers can control to ensure efficient delivery of the system. The ambulance relocation and dispatch policies that are studied in dynamic ambulance relocation models also significantly contribute to improving the response time of EMS. In this paper, we review dynamic ambulance relocation models from the perspective of dispatch policies. The connection between the reviewed ambulance dispatch policies and real-life policies is highlighted. Our ambulance model is based on the modified maximal covering location problem (MCLP). It is used to examine the commonly used dispatch policy and the proposed method of free-ambulance exploitation to further improve urgent call response time. Simulation results show that the proposed method can reduce the response time of urgent calls, especially during low-ambulance-supply period. We also compared the performance of EMS with and without reroute-enabled dispatch.

Techniques for vibration control of a flexible robot manipulator

This paper presents investigations into the applications and performance of positive and negative input shapers in command shaping techniques for the vibration control of a flexible robot manipulator. A constrained planar single-link flexible manipulator is considered and the dynamic model of the system is derived using the finite element method. An unshaped bang-bang torque input is used to determine the characteristic parameters of the system for design and evaluation of the input shaping control techniques. The positive and specified amplitude negative input shapers are designed based on the properties of the system. Simulation results of the response of the manipulator to the shaped inputs are presented in the time and frequency domains. Performances of the shapers are examined in terms of level of vibration reduction, time response specifications and robustness to parameters uncertainty. The effects of derivative order of the input shaper on the performance of the system are investigated. Finally, a comparative assessment of the impact amplitude polarities of the input shapers on the system performance is presented and discussed.

A Path Tracking Algorithm Using Future Prediction Control with Spike Detection for an Autonomous Vehicle Robot

Trajectory tracking is an important aspect of autonomous vehicles. The idea behind trajectory tracking is the ability of the vehicle to follow a predefined path with zero steady state error. The difficulty arises due to the nonlinearity of vehicle dynamics. Therefore, this paper proposes a stable tracking control for an autonomous vehicle. An approach that consists of steering wheel control and lateral control is introduced. This control algorithm is used for a non-holonomic navigation problem, namely tracking a reference trajectory in a closed loop form. A proposed future prediction point control algorithm is used to calculate the vehicles lateral error in order to improve the performance of the trajectory tracking. A feedback sensor signal from the steering wheel angle and yaw rate sensor is used as feedback information for the controller. The controller consists of a relationship between the future point lateral error, the linear velocity, the heading error and the reference yaw rate. This paper also introduces a spike detection algorithm to track the spike error that occurs during GPS reading. The proposed idea is to take the advantage of the derivative of the steering rate. This paper aims to tackle the lateral error problem by applying the steering control law to the vehicle, and proposes a new path tracking control method by considering the future coordinate of the vehicle and the future estimated lateral error. The effectiveness of the proposed controller is demonstrated by a simulation and a GPS experiment with noisy data. The approach used in this paper is not limited to autonomous vehicles alone since the concept of autonomous vehicle tracking can be used in mobile robot platforms, as the kinematic model of these two platforms is similar.

Enhancements of PECOS Embedded Real-Time Component Model for Autonomous Mobile Robot Application

Recent@, Component-Based Sofiare Enxineering (CBSE) has becoming a poptrlar approach.for developing embedded sofiare. In CBSE, a component model is required to specifY the standards and conventions imposed on developers of components. Indushial cornponent models such as CORBA, CUM and JavaBeans are general!^ not stritable for embedded real-time (ERT) Vstenis. Consequently, a number of component models slritahle for CBSE ofERT sofiare such 0.7 PBO, Koala, PECOS and ReFIex are introduced. Assessments of the PECOS component model were conducted to evaltrate the suitabiliw of PECOS component model for adoption in CRSE of autonomous mobile-robot (AMR) software. The as.~e.ssments emphasize on three requirentent.y: facilitates predictable real-time performance, support for resource constraint systems, and support plarfonn-independent implementation. Three enhancemenlr were proposed for the PECOS component model. These enhancements were implemented on a real m-wheeled mobile robot. and resul~f show that, the PECOS cornponent model together with the proposed modifications can generate application siritable for resource constrained AMR vstem.r, the new mapping of component behavior to tash process can be used to guarantee the nm-time predictabili(v and perjormance, and the new irnplenientation pamework proposed enable plarform independent development of AMR sofiare.

Market-based approach for multi-team robot cooperation

The scalability of market-based approaches in multi-robot system coordination enables an assigned task to be decomposed into subcomponents achievable by individuals or subteams within the team. However, in some potential multi-robot system applications, particularly search and rescue operations, this can involve deployment of multiple teams of robots from different parties to work side by side. Each team of robots is independently managed by its operator. A loose collaboration among teams of robots is needed to increase the efficiency of a task completion. This work presents a variant architecture of multi-robot systems using Contract Net Protocol to address the coordination among multiple teams of robots. The system is named a multi-team robot system. It places emphasis on a teams data security in communication where each team operates on a respective communication network while maintaining their collaboration. The method of task coordination is explained in detail and verified on a physical mobile robot platform.

A Component-Oriented Programming for Embedded Mobile Robot Software

Applying software reuse to many Embedded Real-Time (ERT) systems poses significant challenges to industrial software processes due to the resource-constrained and real-time requirements of the systems. Autonomous Mobile Robot (AMR) system is a class of ERT systems, hence, inherits the challenge of applying software reuse in general ERT systems. Furthermore, software reuse in AMR systems is challenged by the diversities in terms of robot physical size and shape, environmental interaction and implementation platform. Thus, it is envisioned that component-based software engineering will be the suitable way to promote software reuse in AMR systems with consideration to general requirements to be self-contained, platform-independent and real-time predictable. A framework for component-oriented programming for AMR software development using PECOS component model is proposed in this paper. The main features of this framework are: (1) use graphical representation for components definition and composition; (2) target C language for optimal code generation with resource-constrained micro-controller; and (3) minimal requirement for run-time support. Real-time implementation indicates that, the PECOS component model together with the proposed framework is suitable for resource constrained embedded AMR systems software development.

A New Tuning Method for Two-Degree-of-Freedom Internal Model Control under Parametric Uncertainty

Abstract Internal model control (IMC) yields very good performance for set point tracking, but gives sluggish response for disturbance rejection problem. A two-degree-of-freedom IMC (2DOF-IMC) has been developed to overcome the weakness. However, the setting of parameter becomes a complicated matter if there is an uncertainty model. The present study proposes a new tuning method for the controller. The proposed tuning method consists of three steps. Firstly, the worst case of the model uncertainty is determined. Secondly, the parameter of set point controller using maximum peak (Mp) criteria is specified, and finally, the parameter of the disturbance rejection controller using gain margin (GM) criteria is obtained. The proposed method is denoted as Mp-GM tuning method. The effectiveness of Mp-GM tuning method has evaluated and compared with IMC-controller tuning program (IMCTUNE) as bench mark. The evaluation and comparison have been done through the simulation on a number of first order plus dead time (FOPDT) and higher order processes. The FOPDT process tested includes processes with controllability ratio in the range 0.7 to 2.5. The higher processes include second order with underdamped and third order with nonminimum phase processes. Although the two of higher order processes are considered as difficult processes, the proposed Mp-GM tuning method are able to obtain the good controller parameter even under process uncertainties.

Refine PID tuning rule using ITAE criteria

This paper discusses an approach to tune the PID controller parameters using the optimization method. The method involves analytically calculating the gain of the controller (Kc), integral time (Ti) and the derivative time (Td) for PID controlled systems whose process is modeled in first order lag plus time delay (FOLPD) form. A mat lab program is used to find the optimum value of the PID controller parameters which can achieve most of the systems requirements such as reducing the overshoot, maintain a high system response, achieve a good load disturbances rejection and maintain robustness. The objective function is selected so as to minimize the integral of Time Absolute Error (ITAE) performance index. A comparison between the proposed tuning rules and the traditional tuning rules is done through the Matlab software to show the efficiency of the new tuning rule.

Service based meta-model for the development of distributed embedded real-time systems

The development complexity of Distributed Embedded Real-Time Systems (DERTS) can be reduced by the use of Service-Oriented Computing (SOC). However, the existing modeling methods allow modeling of either DERTS or SOC concepts and there is a lack of meta-model for Service-Oriented development of DERTS. This paper proposes a service-based meta-model for DERTS, along with the constraints of the elements of the meta-model. A Smart Home case study was designed to validate the meta-model. This meta-model could not only be beneficial for Service-Oriented development of DERTS, but can also be used at the Platform Independent Model (PIM) level of MDD.

Early-Life Cycle Reuse Approach for Component-Based Software of Autonomous Mobile Robot System

Applying software reuse to many embedded realtime systems, such as autonomous mobile robot system poses significant challenges to industrial software processes due to the resource-constrained and realtime requirements of the systems. An approach for early life-cycle systematic reuse for component-based software engineering (ELCRA) of autonomous mobile robot software is developed. The approach allows reuse at the early stage of software development process by integrating analysis patterns, component model, and component-oriented programming framework. The results of applying the approach in developing software for real robots show that the strategies and processes proposed in the approach can fulfill requirements for self-contained, platform-independent and real-time predictable mobile robot.