Introduction to Mechatronics System

What is Mechatronics?

Mechatronics is a comprehensive system that combines mechanical and electrical elements. It involves the integration of mechanics, electronics, computing, and control to effectively supervise the entire structure. The term 'Mechatronics' was coined by a Japanese engineer named Mr. Tetsuro Mori in 1969 while working at Yaskawa Company in Japan. The word itself is derived from a combination of 'Mechanics' and 'Electronics'. Mechatronics engineering represents the synergistic integration of mechanical engineering, electronic engineering, and computer engineering.

Previously, the definition of mechatronics was described as "The synergistic integration of mechanical engineering with electronics and intelligent computer control in the design and manufacturing of industrial products and processes." However, the modern definition of mechatronics states that "A mechatronics system is not merely a combination of electrical and mechanical systems, nor is it solely a control system. It is a complete integration of all these components."

In contemporary times, the application of mechatronics systems spans various fields such as machining and the automobile industry, medical applications, defense applications, sports applications, and home appliances, among others. This indicates that the mechatronics system is employed in nearly all areas of modern appliances. In some cases, the mechatronics system has replaced traditional mechanical systems with electronic counterparts. For instance, in automobiles, automatic fuel injection methods are now utilized instead of mechanical fuel injection methods. Similarly, 'Intelligent Controllers' are employed in domestic appliances like air conditioners and washing machines.

The image below illustrates the synergistic integration of the mechatronics system. 

The mechatronics system has gradually developed to its current state through the continuous improvement of earlier mechanical engineering. The introduction of advanced technologies and additional devices has contributed to the evolution of modern mechatronics engineering. The integration of microcontrollers, programming software, and various electronic devices has made mechatronics engineering smarter and more intelligent. The image below depicts the evolution of mechatronics engineering.  

The Japan Society for the Promotion of Machine Industry (JSPMI) has classified mechatronics system-controlled devices into four basic categories:

Class I: These devices consist of different electronic devices that functionally operate machines to improve efficiency, such as CNC machines.

Class II: The operating system of these machines is solely managed by various electronic devices. For example, a modern sewing machine.

Class III: In these devices, the traditional operating system has been completely replaced by an electronic device. For instance, a digital clock.

Class IV: These machines are designed from the outset, combining different electronic and mechanical devices. For example, photocopiers.

The mechatronics system finds wide application in various areas, including

• Manufacturing Applications: NC and CNC machines.
• Transport Applications: Automobiles, high-speed trains, Segways.
• Robotics Applications: Automated material collection arm, robots.
• Medical Applications: Prosthetics, pacemakers.
• Defense Applications: Unmanned aerial vehicles, stealth bombers.
• Home Applications: Washing machines, microwave ovens, air conditioners.

Basic components used with the Mechatronics system

The basic components used in a mechatronics system are sensors, actuators, controllers, and the mechanical system. The 'mechanical system' carries out different tasks under the command of the controller, such as controlling the braking system of an automobile, facilitating automatic workpiece changes in a CNC machine, or enabling robotic arm movements. The controller serves as the central organizer of the mechatronics system and possesses complete information about the current status of all connected devices. This information is typically gathered through various sensors, including speed, temperature, displacement, etc. Sometimes, when the controller receives a signal from a sensor that is not immediately understandable, it becomes necessary to convert it using an analog-to-digital converter.

The controller acts as the 'brain' of the mechatronics system. It analyzes user signals or commands as well as signals from different sensors to generate output signals and operate various actuators associated with the system. Commands can be inputted through different means, such as command button switches or touch screens. Sometimes, instructions are automatically executed through a program stored in the controller. An actuator, such as solenoid valves or stepper motors, assists in completing different mechanical tasks based on the signals received from the controller. These actuators typically utilize various mechanical power transmission systems. The image below illustrates the four basic components of a simple mechatronics system.

Controller: In a mechatronics system, the controller is responsible for managing different tasks. For simple mechanisms, the system is managed with the help of basic electrical elements and a microcontroller unit (MCU) serving as the controller. In more complex mechanisms, a personal computer may also be used as the controller. The MCU, also known as an 'embedded' system, is employed in some advanced mechatronics systems where synchronization between different mechanisms and appliances within the system is necessary. In such cases, a programmable logic controller (PLC) is utilized as the controller. Advanced mechatronics systems are a combination of hardware and software and can sometimes operate independently without human intervention. Hardware refers to the physical devices associated with the system, while software consists of written instructions stored in the system's computer or controller. In some cases, firmware, a series of instructions stored in ROM and not easily changed, is used with mechatronics systems. Later, detailed discussions will be conducted on different controllers and control mechanisms used in mechatronics systems.

 Sensor: The controller receives information about the present state or status of all devices connected to the mechatronics system through sensors. Signals or information from these sensors are typically sent directly to the controller. Sometimes, these signals pass through a suitable converter to make them understandable to the controller. Sensors can be classified into different categories, such as contact type and non-contact type, as well as digital or analog types. Further discussions will be conducted on the various sensors used in mechatronics systems separately.

Actuator: In a mechatronics system, an actuator is a device used for various movements and functions. Different types of actuators, such as linear actuators and rotary actuators, are employed based on the design and nature of the system's work. Actuators can be categorized into three types based on their actuating procedure: electrically operated, hydraulically operated, and pneumatically operated actuators. A separate chapter will provide an extensive discussion of different actuators.

Mechanism: In a mechatronics system, the term "mechanism" refers to the movement of different elements associated with that system in a specific direction or distance. Examples include robotic arm movements or the automatic opening and closing of a door in a machine. Various actuating methods, such as electrical, hydraulic, and pneumatic systems, are employed for the movement of these elements in mechatronics systems. A later discussion will focus on different mechanisms used in mechatronics systems.

How the mechatronics system works

A mechatronics system can be simple or complex depending on its structure and requirements. Complex mechatronic systems typically utilize a microcontroller or programmable controller, while simpler systems may not require a separate controller. Based on the functioning procedure and structural design, mechatronics systems can be classified into two types: open-loop and closed-loop systems. In an open-loop system, the signal from the controller to the actuator is not verified to ensure that the work has been properly completed. This means that no feedback devices are used in open-loop control systems. In contrast, closed-loop systems always incorporate feedback devices, allowing the controller to determine if the work has been completed accurately. For example, an automatic tap water system operates on an open-loop system, whereas a CNC machine functions on a closed-loop system. Instructions in a mechatronics system are typically provided through a controller. They can be given directly through switches or touch screens, or through a program stored in the controller's memory. After receiving instructions from the controller to perform a specific task, the controller delivers signals (in the form of voltage) to activate the relevant actuator accordingly. Actuators may directly perform mechanical work by activating or deactivating related mechanisms, or they may utilize different mechanical power transmission systems to complete their tasks. Sensors monitor whether these mechanical works have been properly completed, providing feedback to the controller. In some cases, instructions are also provided to the system automatically through these sensors, enabling automated operation.