单片机类毕业论文设计-英文翻译.doc

单片机类毕业论文设计

英文资料翻译

A modeling-based methodology for evaluating the

performance of a real-time embedded control system

Klemen Perko, Remy Kocik, Redha Hamouche, Andrej Trost

co-design tools. By defining this bridge, we allow for an automatic model

transformation. As a result, we obtain more accurate timing-behaviour

simulations, considering not only the real-time software, but also the hardware

architecture’s impact on the control performance. We show an example with

different model-evaluation results compared to real implementation

measurements, which clearly demonstrates the benefits of our approach.

KEY WORDS: Modeling, Model transformations, Embedded control systems

design, Real-time systems

1. Introduction

hardware (HW) and software (SW) design provide a variety of possibilities for

designing ECSs (e.g., distributed and networked HW, multi-processor systems, a

variety of SW control algorithms and real-time operating systems (RTOSs), etc.)

[1]. It is commonly acknowledged that the designing and verifying of reliable

and efficient ECSs for a particular application are challenging tasks.

1.1. Traditional control-system design

The aim of designing an ECS is to build a computing system that is able to

of interconnected mechanical, electrical and/or chemical elements. A typical

ECS consists of electronic sensors for data acquisition from the plant, a

computing system for processing the control algorithm, and electronic actuators

to drive the plant.

interpretation, which of course depends on the skill of the designer. The

traditional form of ECS design is performed in two separated domains – the

control SW domain and the HW domain – using specific design tools and their

respective system models. In the first domain, control engineers define the

control laws and the SW engineers write the code that executes the operations

affects (by constraining) the SW execution parameters (i.e., sampling periods,

task-execution jitter, etc.).

In the second domain the HW engineers design an HWplatform that will

execute the control SW. The connections of all the sensors and actuators to the

platform are made via the available communication channels. However, because

to actuators can pass through one or more communication channels. A HW

engineer can, in general, choose from among a variety of communication

protocols, and each type introduces different latencies and jitter, which therefore

affects the SW execution. The control engineer cannot, however, evaluate the

effect of these latencies before the system is actually implemented. Hence, the

desired performance of the system may not be achieved, and it is necessary to

some of the advantages offered by modern HW technologies. For instance,

control loops running in parallel, instead of the traditional sequential execution,

could give better performance. Parallel execution can be achieved with the use

of multi-processor or distributed platforms.

possible system implementations (design-space exploration). Appropriate

modeling can significantly shorten the design cycle of an ECS [2].

To overcome the problems introduced by the heterogeneity of design

models and tools, different methodologies and tools were developed [3]. These

methodologies usually provide a means to create a uniform ECS model, simulate

1.2.Proposed control system design

To improve and accelerate the traditional ECS design we propose the

merging of these separated domains. On the basis of this merging, all the actors

in the design process could better collaborate and exchange their data during the

design process, they could do a more thorough design-space exploration and the

design cycle could be made significantly shorter. Instead of developing a new

methodology for ECS design, we propose to upgrade the traditional SW-based

control-system design approach with efficient modeling and design of the HW

platforms. Recently, several methodologies have been developed that concern

HW/SW co-design. These methodologies enable the efficient design of SW and

HW on embedded systems in terms of SW execution speed, HW resources usage,

creating a formal bridge between the existing tools for control-scheduling

co-design and HW/SW co-design. This bridge makes possible model

transformations and the exchange of simulation results between tools for

control-scheduling co-design and HW/SW co-design.