The article discusses the role of mechatronic system in modern society, highlighting their applications in vehicles, robotics, and automated systems. It explores key examples such as airbag safety systems, industrial and mobile robots, and parking garage gates, emphasizing the integration of mechanical, electrical, and computational technologies to enhance efficiency and functionality.
Modern society depends on mechatronic-based systems for its conveniences and luxurious standard of living. From intelligent appliances to safety features in cars (such as airbags and anti-lock brakes), mechatronic systems are widely used in everyday life. The availability of low-cost, compact, and powerful processors in the form of MCUs accelerated the widespread use of mechatronic systems. An example is using embedded controllers to control many of the devices in a vehicle. A list of such applications is shown in Table 1. Note that in a vehicle, an MCU is housed in a unit called an electronic control unit (or ECU), which holds the MCU and some peripherals. Each ECU is configured for a specific function as the ECU to control anti-lock braking.
Table 1 Listing of Sample Applications of Mechatronic Systems in Vehicles
| Application Area | ||
| Safety | Comfort | Power Train |
| • Airbag system | • Door locks | • Engine controls |
| • Anti-lock braking system | • Keyless entry system | • Fuel pump controls |
| • Daytime running light | • Heating system controls | • Fuel sensing controls |
| • Electronic stability controls | • Seat positioning controls | • Gearbox controls |
To further illustrate mechatronic systems, we will discuss four examples: the airbag safety system in a vehicle, an industrial robot, a mobile robot, and a parking garage gate.
Airbag Safety System
The airbag safety system is designed to protect the occupants of a vehicle in the case of a collision, and it consists of three main components: sensors to detect a crash, an ECU to process the sensor signals, and actuators to deploy the airbags. For frontal collisions (see Figure 1), most airbag safety systems use two sensors. A ‘crash’ sensor is located in the crush zone of the vehicle to detect the collision, and a ‘safety’ or ‘arming’ sensor is located in the passenger compartment area to prevent false deployment of the airbag. The signals from these two sensors are fed into the airbag ECU which is typically located in the center console area of the vehicle.
The software in the ECU processes the sensor signals and employs logic to decide if the airbags need to be deployed. If that is the case, then an electrical signal is sent to the airbag canister or inflator which detonates a small amount of igniter compound. The ignition causes a chemical reaction that causes the nylon fabric airbag to be rapidly filled with Nitrogen from the chemicals that are placed in the canister.
Airbag systems also use seat occupancy sensors to detect the presence and weight of the occupant in the front passenger seat. If the seat is not occupied or a low-weight occupant is identified, then the passenger airbag will not be deployed (such as to protect a small person sitting in the front seat from the force of the airbag).
Advanced airbag ECUs can also activate seat belt pretensioners, which are devices that quickly retract and tighten the seatbelts, to restrain the vehicle occupants in their seats in the case of a collision. It is important to note that it takes less than 50 milliseconds (ms) from the time the collision is detected by the airbag sensors to the time the airbag is fully inflated, so it is of utmost importance that the control software for an airbag system operates with no delay.
As explained previously, the airbag safety system is a sophisticated mechatronic system that uses various sensors in combination with a control unit and actuators that need to work reliably and rapidly.
Figure 1 Frontal collision sensors in an airbag system
Industrial Robots
Industrial robots are a prime example of mechatronic systems, whether they are fixed in one location or mobile. Figure 2 is an illustration of an industrial robot arm, which embodies the core principles of mechatronics.
A robot, in essence, is a mechanical apparatus that can be programmed to execute a wide range of tasks and applications. The fundamental components of a robot system consist of the controller and the mechanical arm.
The controller assumes several crucial functions within the robotic system, including managing the user interface, programming operations, and controlling the movements of the arm. Its responsibilities encompass facilitating communication between the user and the robot, enabling the programming of various tasks, and overseeing the precise execution of these tasks by the mechanical arm.
The mechanical arm itself is typically composed of multiple interconnected mechanical links, joined together by joints. Each of these links is driven by an actuator, which imparts motion to the arm. Furthermore, each actuator is equipped with a feedback sensor that provides valuable information regarding the position of its corresponding link. This sensor-based feedback mechanism allows for accurate and precise control of the robotic arm’s movements.
A multi-link robot, due to its intricate design and structure, necessitates a sophisticated level of coordination among the individual links. This coordination is primarily facilitated by the control software, which operates by processing input data derived from the desired motion of the arm, as well as the feedback received from the sensors.
To enhance a robot’s ability to adapt to variations within its operating environment, additional sensors are typically incorporated into the system. Vision sensors, for example, enable the robot to perceive and interpret visual information, while proximity sensors aid in detecting the presence or proximity of objects. By utilizing such additional sensors, the mechatronic system enhances the robot’s perception and understanding of its surroundings, allowing it to effectively navigate and interact within its environment.
In summary, the mechatronic system of an industrial robot encompasses most, if not all, of the components depicted in Figure 3. Through the seamless integration of mechanical components, actuators, sensors, control software, and additional sensing capabilities, industrial robots exemplify the synergy between mechanical engineering, electronics, and computer science.
Figure 2. Industrial robot
Figure 3. Typical Components of a Mechatronic System
Mobile Robots
Mobile robots are currently being used in a wide diversity of applications. Whether vacuum cleaning, assisting soldiers in combat operations, or delivering food and medicine in hospitals, their use is increasing. Similar to their fixed counterparts, a mobile robot consists of several modules that are commanded by a controller.
Due to their operation in unstructured environments, mobile robots rely heavily on sensors to guide them in navigation and to avoid obstacles. Examples of sensors used by mobile robots include ultrasonic proximity sensors, vision sensors, and global positioning system sensors.
An example of a mobile robot is the Roomba® vacuum-cleaning robot (see Figure 4) made by iRobot® Corporation. The Roomba has a cylindrical shape, two-wheel modules, and several sensors (see Figure 5) including cliff sensors, a wall-following sensor, a floor tracking sensor, and a camera. The infrared or cliff sensors are located at the edge of the robot that let the robot know when it is close to a ‘cliff’ such as stairs. These cliff sensors measure the distance between the robot base and the floor by sending an infrared light that is reflected from the floor surface and detected by receivers on the robot. If the receiver does not receive any signal, then the robot figures out that it is close to the ledge, and backs away from that position.
The wall-following sensor also uses infrared lighting to maintain a given distance from a wall. The floor tracking sensor measures the distance and direction that the robot has traveled. The control system on the Roomba uses advanced algorithms to combine data from several sensors to create a map of the room that is being cleaned and to navigate around obstacles. The Roomba has all the main components of a mechatronic system: actuators (wheel modules), sensors, and a controller.
Figure 4. Roomba ® vacuum cleaning robot
Figure 5. Sensors on Roomba ® vacuum cleaning robot
Parking Gate
A parking garage gate is another example of a mechatronic system that involves several components (see Figure 6). The system has an electric motor to raise and lower the gate arm. It also has a proximity sensor to prevent the gate from striking people and vehicles. In addition, it has a controller in which software is used to run the gate in different operating modes.
Typically, a parking garage gate operates as follows: The user presses a button to get a ticket or swipes a card in a card scanner. Once the ticket is picked up by the user or the card is validated, the gate arm rotates upward. The gate arm remains in a raised position until the vehicle has completely cleared the gate, at which point the gate drops down. The operation of each stage of this system is dependent on sensor feedback and timing information. The controller for this system cycles between the different operating stages each time a vehicle needs to enter the parking garage.
Figure 6. Parking Gate Example
Mechatronic System Key Takeaways
The previous examples illustrate a wide range of mechatronic systems. Mechatronics, the interdisciplinary field that combines mechanical engineering, electrical engineering, and computer science encompasses numerous enabling technologies crucial to the design, operation, and control of modern smart systems. These technologies include signal processing, system interfacing, sensor integration, drive technology, actuation systems, software programming, and motion-control systems.
The future of mechatronics is quite promising. Mechatronics will continue to play a vital role in the development of advanced robotics and automation systems. These systems will become more sophisticated, and capable of performing complex tasks with greater precision, agility, and adaptability with applications in different industries, including manufacturing, healthcare, agriculture, and logistics.
The integration of mechatronics with the Internet of Things (IoT) will enable the development of smart and interconnected devices that allow them to collect and exchange data, perform real-time analysis, and respond intelligently to their environments. This integration will lead to advancements in areas such as smart homes, autonomous vehicles, and wearable technology.
Overall, mechatronics will continue to drive innovation and contribute to the advancement of numerous fields. Its interdisciplinary nature and integration with emerging technologies will shape the future of robotics, automation, and smart systems, leading to improved efficiency, convenience, and functionality across various sectors.