figure shows a typical microprocessor-based mechatronic application. It consists of many subsystems, including the following.
- mechanical subsystem. this constitutes the machine or device being controlled. The device itself may involve a great number of internal individual or interrelated mechanisms with their individual subsystems.
Figure 1.1 components of a mechatronic system
- Sensors to measure the controlled variables. Sensors of all types provide the computer with information. it needs to perform monitoring and control tasks.
- Actuators convert digital signals into physical or chemical quantities as required to correct errors in meeting the required performance.
- Instrumentation subsystem. This involves all necessary signal-conditioning (SC) circuits to interface actuators, sensors, and other devices to the control computer.
- Control computer. Proper control of a process requires intense processing of information representing a complex interplay between sensing the environmental conditions that affect the outcome of the process, interpretation of the sensed values, recognising effect of these values on the integrity of the operation, and initiating a response by signalling the actuators to take the necessary corrective actions. Coordinating all these activities is the responsibility of the control computer, which involves embedded microprocessor systems. it handles the flow of information between the various components by integrating the software and hardware dedicated to controlling the process in question. The hardware, also referred to as the target system, consists of all computers needed to manage the inputs and outputs of the mechatronic device. This includes sensors, actuators, mechanical components, power supplies, control computer, and the SC circuits interfacing the computer with the sensors and actuators. As a first step, a prototype of the hardware may be built using wire-wrapped boards to test the application software before the final product is realised. The software manages all activities of the target system. It consists of the program (or code), which is developed to meet the application requirement. Development of the application code can begin concurrently with the hardware prototype development once the system specifications have been completed. The code could be modified as it is developed to reflect design changes and/or new requirements as they emerge. The application code may be developed using machine language, assembly language, or a high-level language such as C. The machine code, or object code, contains binary codes that represent the instructions to the computer. It is the only language the microprocessor can understand and execute. High-level languages such as C use words and statements that are easily understood. A program written in a high-level language must be translated into executable machine language using a program called a compiler. Assembly language represents a middle ground between the extremes of machine language and the high-level language. An assembly language program is written using mnemonics in which each statement corresponds to a machine instruction. The assembly program must be translated into machine language by a special program called an assembler.