Basic knowledge of mechatronics

Basic knowledge of Mechatronics

Mechatronics is a technology that controls machines that incorporate various mechanical components and electronic devices. In this series, we will explain 9 times more important mechatronics due to further development of robot industry and AI / IoT technology. This time, which is the first time, we will learn about mechatronics from definitions and etymologies, familiar examples, and changes.

Table of contents

Part 1: What is Mechatronics

Part 2: Components of mechatronics

Part 3: Mechanism technology of mechatronics

Part 4: Mechatronics actuator technology

Part 5: Mechatronics electrical and electronic circuit technology

Part 6: Sensor technology of mechatronics

Part 7: Control technology of mechatronics

Part 8: Automation and robot technology

Part 9: Cooperation of mechatronics and IoT, AI

Part 1: What is Mechatronics?

The definition of mechatronics is not clear. There are 10 different colors depending on the position, age, and application of the person involved in product design. Generally speaking, mechatronics refers to a technology that automatically realizes a given purpose (motion) by combining mechanical engineering (mechanical), electrical / electronic engineering (electric), information engineering and control engineering (software). Is a common recognition. It is also a system integration technology that brings together technologies that span multiple fields.

Machines such as automobiles, home appliances, and robots that we are familiar with are equipped with various mechanical parts and electronic devices. Mechatronics is the technology that controls these and achieves the desired movement. In addition, Mechatronics continuously creates new areas while absorbing technologies in different areas. For example, in the field of robotics, there is an effort to create a human-like existence by incorporating cognitive / psychological engineering and artificial intelligence engineering into the basic mechatronics technology. In the future, if technological innovations such as IoT and AI progress further, fusion with completely new fields will occur.

2. A familiar example of mechatronics

In order for a machine to perform complicated operations, it is necessary to combine mechanical element parts such as cams and links in a complicated and precise manner.

By replacing the mechanism part with an electric / control system, complex operations can be realized in a short process. Furthermore, while the combination of mechanical elements allows only limited movement, the electrical and control technology allows the machine to operate at a higher level and broadens the range of functions.

In recent years, by replacing the engine with an electric motor, an electric vehicle with a significantly reduced number of parts has emerged, and a new revolution has been reached toward the practical and general-purpose use of automated driving. In this way, mechatronics will be the basis of technology and will bring about great changes to society.

3. Transition of mechatronics

Mechatronics is inextricably linked to manufacturing trends. Conventionally, FA technology (Factory Automation) that automates the manufacturing process in factories has been emphasized. Nowadays, the technology for making high value-added products such as products that support human beings and products that consumers have never thought about is required, and the needs for manufacturing are changing. Let's look back at the transition of mechatronics technology, which is a fusion of the trends of the times and mecha-electronics / software.

・ First Mechatronics Revolution (from around 1960)

It is an era where we focused on FA that replaces human labor work with automation (machine). By electrically controlling mechanical systems such as links, cams, and gears, we have achieved mass production of a small number of products.

・ Second Mechatronics Revolution (around 1980)

It was an era when we focused on making things that sell well in a timely manner. We have achieved high-mix low-volume production by incorporating electric technology such as transistors, ICs, and LSIs (large-scale integrated circuits).

・ The 3rd Mechatronics Revolution (around 2000)

It is an era where we focused on cost reduction and high functionality in order to immediately respond to changes in human lifestyle. By combining servos with a simple mechanism and using embedded software with a microcomputer, we have achieved a variety of variable-volume production.

・ Fourth Mechatronics Revolution (Recently)

With the development of IoT and AI, we are in an era where high value-added products centered around network technologies are required. In mechatronics, mechanical design and digital control system are unified, and in electronics, miniaturization and integration are sufficiently advanced, and software is also highly sophisticated. Various types of mass production, one type of one volume production are required.

As for mechatronics technology in the future, technical difficulty will increase and the required products will change. Designers will be required to have a deep understanding of system integration technology as well as abundant creativity and a flexible attitude.

Part 2: Components of mechatronics

. Mechatronics consists of a combination of mecha, electric and software. By knowing the roles of each and the precautions when combining them, you can prevent problems before they occur.

1. Human and mechanical systems

A system is a mechanism that functions by inputting some kind of energy or information and outputs operation or information. Since humans ingest food, think and act based on information from the outside world, they can be regarded as a kind of system. When the mechanical system gets energy, it senses information from the outside world with a sensor and makes a decision with a computer to realize work. Humans and mechanical systems are similar in terms of systems.

Mechatronics is a mechanical system, which mainly consists of six elements.

A mechanism is a mechanism / structure that enables a certain movement and corresponds to the human skeleton. An actuator is a drive that moves a machine and is equivalent to a human muscle. Electric circuits and electric power sources send information and electric power to the mechanism and drive unit, and are equivalent to human nerves and internal organs. Sensors measure the movement of machines and correspond to the human sense organs such as the eyes, nose, ears, mouth, and skin. Computers are the brains of humans, performing calculations and decisions to control movement. Control technology (algorithm) determines how the robot works and is equivalent to human thought. In mechatronics, these multiple elements need to work smoothly.

2. Three fields supporting mechatronics

Mechatronics consists of the fields of mecha, electric, and software. When making mechatronics products, the combination and balance of these three fields is important.

Mechanisms are in the field of mechanical engineering, where mechanisms and structures are carefully combined and mechanical actions such as movements are also considered. Electronics is an area of electrical and electronic engineering that considers the compatibility of signals, actuators, power supplies, wiring, etc. Electronics also act as an intermediary between mechanisms and software. The mechanical and electrical fields are hardware related technologies.

Part 3: Mechanism technology of mechatronics

1. What is a mechanism?

Mechanism was once translated as mechanism or mechanics. In recent years, it has been broadly regarded as a mechanical element that transmits motion between parts. When a part transmits motion to a part, it combines three unit movements: straight (translation), rotation, and swing (swirl). Fig. 1 shows a representative example of the mechanism, which is a slider / crank mechanism that converts rotation to linear motion and a lever crank mechanism that converts rotation to swing motion. A rotating link is called a crank and an oscillating link is called a hate. Even with the same link, the name changes depending on the movement and role.

Fig 1

The number of directions in which an object can be moved by a mechanism is called the degree of freedom. When the crank (rotation) side is the driving node and the slider (straight line) and lever (swing) to which motion is transmitted are the driven nodes, each of the dependent nodes moves in only one direction, so there is one degree of freedom. For example, in the case of a human arm, there are two swings in front and back of the shoulder and up and down, and 3 degrees of freedom by turning the entire arm, 2 degrees of freedom by swinging and bending the elbow and turning by turning the forearm beyond the elbow, and bending of the wrist. Two degrees of freedom with extended swing and side swing. There are a total of 7 degrees of freedom.

2. Role of mechanism

In the past, the mainstream of mechanical systems was the mechanical and complex combination of mechanical element parts such as cams and links. This was mostly composed of a mechanism. Electronic control is widely used in recent mechatronics products. However, it is not possible to make a product with only electric or software technology. It is the mechanism that directly touches the work or physically works. Mechanisms have an important role in mechatronics.

In order for mechatronics products to operate properly, it is necessary to determine the basic functions and select the mechanism that realizes them. For products that move people or objects, a mechanism that transmits driving force and rotation from the actuator to the wheels and propeller is required. Robots require a skeleton to perform specific tasks by adjusting force, speed, and position with a transmission mechanism.

4th: Mechatronics actuator technology

There are four elements to consider in mechatronics product design:

Mechanism
Actuator
Sensor
Control And we need to consider the interface. The actuator that drives the mechanism plays a central role in mechatronics. In addition to the concept of actuators, we will explain motors and hydraulic / pneumatic actuators that are often used in industry. 1. What is an actuator?

An actuator is a device that generates motion from a physical power source such as electricity, electromagnetic waves, or heat. The role of the actuator is energy conversion. For example, electric energy from a power source is converted into mechanical energy such as rotational motion by an actuator.

A typical actuator is a motor. Other actuators are solenoids that receive the energy of a magnet and convert it into linear motion, and shape memory alloys that receive electric current and convert into expansion and contraction motion. Actuators are essential in the design of mechanical systems. However, since the lineup is wide, it is necessary to select the most suitable one according to the output, control method, application, cost, etc.

2. Motor type

A typical actuator is a motor. A motor is a general term for devices that convert electrical energy into mechanical energy. Also called an electric motor. Motors are used as power sources in many industrial machines and equipment. There are various types of motors, and they are generally classified by signal, power supply, conversion principle, output, structure, appearance, etc.

Signal classification: single, frequency, pulse
Power supply classification: DC power supply, AC power supply (single-phase), AC power supply (three-phase)
Classification by conversion principle: electromagnetic, electrostatic, ultrasonic, etc.
Classification by output: Ultra-small motor (3W or less), small motor (3W to 100W), medium-sized motor (100W to several kw), large motor (several kW or more)
Structure / appearance: Rotation type / straight type, size of structure, rotation range, etc

5th: Mechatronics electrical and electronic circuit technology

Circuits can be classified into two types, electrical circuits and electronic circuits, depending on how passive and active devices are used. An element that has no ability to act on voltage and frequency and that follows changes in voltage and frequency is called a passive element. Typical examples of passive elements are resistors, coils and capacitors. The circuit constructed using these is an electric circuit. An element that has the ability to act on the voltage and frequency given by the power supply is called an active element. Typical examples of active devices are ICs, diodes, and transistors. Active elements can also control voltage and frequency, amplify electricity, and convert energy. An electronic circuit is a circuit that combines passive elements and active elements.

Consider an electric stove that produces heat. ON / OFF of a simple switch can be made only by an electric circuit. An electronic circuit is also required to control the operation, such as setting the output strength to match the room temperature. Mechatronics makes use of both electrical and electronic circuits.

2. Analog and digital circuits

Electrical and electronic circuits handle electrical signals. Electrical signals can be analog or digital ( Fig ). The analog signal takes a continuous value like a wave. For example, the values handled by mechatronics include length, weight, force, voltage, and current, and these physical quantities are continuous quantities. Digital signals, on the other hand, have two values, 0 and 1, which are discrete quantities. Digitally, a value of 0.5 is assigned to either 0 or 1. The reference value for distribution is called the threshold value. For example, if you set a threshold value between 0 and 1, it will be judged as 1 if it is 0.5 or more and 0 if it is less than 0.5.

In an analog circuit that handles analog signals, information (signal) processing is performed by making use of continuous changes in the physical quantities (voltage and current) of the circuit. A digital circuit that handles digital signals determines whether it is 1 or 0 depending on whether the physical quantity is greater than or less than a threshold value. Because digital signals are more reproducible and easier to process than analog signals, computer calculations are performed digitally.

3. Analog / Digital conversion and Digital / Analog conversion

In mechatronics systems, it is necessary to convert signals from analog to digital and from digital to analog in order to connect the elements. The conversion from analog to digital is called Analog / Digital conversion, and the conversion from digital to analog is called Digital / Analog conversion.

The sixth: Sensor technology of mechatronics

it is sensor technology. Sensors are used everywhere in mechatronics in recent years. The word sensor comes from the English Sensory. It is equivalent to the human senses and is essential for mechatronics.

1. What is a sensor?

Sensor technology is a technology for collecting the information necessary for operating machines and robots. Sensors correspond to the five human senses (visual, auditory, taste, olfactory, and tactile), and multiple sensors are used to move machines and robots.

Sensors that correspond to vision (eyes) are most often used in mechatronics. Typical examples are optical sensors and infrared sensors. More advanced image sensors and cameras are closer to the functions of the human eye. An ultrasonic sensor is a typical sensor equivalent to hearing (ear). Ultrasonic sensors are used not only to detect sound, but also to measure distance and position. Typical sensors that correspond to the sense of touch (skin) are the force sensor and the tactile sensor. Strain gauges are representative of force sensors, and tactile sensors include pressure sensors. Sensors that correspond to sight, hearing, and tactile mainly measure physical quantities such as light, waves, and displacement.

On the other hand, the sensors corresponding to the taste (tongue) and smell (nose) mainly detect the stoichiometry. There are few chemical sensors that have been put into practical use, and research and development is proceeding as next-generation sensors. Mechatronics sensors are designed to detect the information required for movement and control of mechatronics. Therefore, it is most often to detect the physical quantity.

2. The role of the sensor

Sensors have two major roles. One is to detect the condition of the target. The other is to replace it with a signal that the computer can handle.

The detection of the target state means that the sensor detects the movement of the mechanism and the situation around the machine (target state) and outputs the result. Physical quantities that represent the state of the object include force, velocity, acceleration, and position. After sensing the physical quantity, the sensor transforms the characteristics of the physical quantity using physical laws and effects. For example, the voltage effect produces a voltage in response to the strain produced by applying pressure. The tactile sensor uses the voltage effect. Table 1 shows an example of the relationship between the input and output of the sensor and the physical effects used.

Table 1: Sensor input / output relationships and physical effects used

		input
		light	Machine quantity	heat	Electrical	Magnetic
output	light	Photo luminescence	Photoacoustic effect	Heat radiation	Photoelectric effect	Magneto-optical effect
	Machine quantity	Photoelastic effect	Coriolis law	Frictional heat	Piezoelectric effect	Magnetostriction effect
	heat	Blackbody radiation	Thermal expansion	Rigi Leduc effect	Pyroelectric effect	Curie- Weiss law
	Electrical	Electro luminescence	Piezoresistive effect	Peltier effect, Thomson effect, Seebeck effect	Ohm's law	Hall effect
	Magnetic	Faraday effect, Cotton Mouton effect	Magnetostriction effect	Etchshausen effect	Magnetoresistive effect, Hall effect	Josephson effect

The seventh: Control technology of mechatronics

In recent years, highly automated products have been developed that cannot be achieved simply by combining mechanical elements. Behind this is the development of computers and subsequent advances in control technology. We will explain the control technology that is indispensable for automation of machines and devices.

it is a combination of contra (reverse) and roll (turn), which means that you can control something by controlling it. There are two types of control in mechatronics:

Manual control in which the machine is operated directly by human power, and automatic control in which the machine is operated by a circuit or computer.

There are many control theories in automatic control. This can also be divided into two types: classical control and current control. Currently, the most widely used is classical control. There are two types of classical control: sequence control and feedback control. For example, in the case of a washing machine, when a start command is given by the start button, sequence control is to realize the operation in a predetermined order. On the other hand, like an air conditioner, when you press the start button, feedback control is to constantly compare the set temperature with the current temperature to reach the target temperature.

Classic control is one response (one output signal) to one command (one input signal). Since it is a simple system control that outputs B when A is input, it is not possible to consider changing the output even if the control target receives noise or vibration. In contrast, modern control handles multiple output values for multiple input values. Hyundai control is a theory in which even if multiple disturbances (such as vibrations) occur in the controlled object, the output can be brought close to the target value with high accuracy.

The eighth: Automation and robot technology

History of automation systems and industrial robots

Many automation systems and industrial robots are operating in factories, and products are automatically made. Automation is a field that has developed rapidly with high economic growth. Especially in the automobile and automobile parts industries, automation has been promoted by making machines perform monotonous repetitive work. People are freed from simple labor and can focus on tasks that only humans can do. As a result, work efficiency and productivity improved, leading to product cost reduction. The automation system is a large-scale facility suitable for mass production of small variety and is still used in many industries.

As we move into the low-growth era and shift to high-mix low-volume production, the introduction of small and medium-sized production lines will increase. That is where industrial robots appeared. The robot has been able to handle the ever-changing types and quantities of products by performing the handling and precision assembly work that had been done by human hands.

The ninth: Cooperation of mechatronics and IoT, AI

I will explain the collaboration between mechatronics and IoT / AI. The success of automated systems that operate on behalf of people and industrial robots that work on behalf of human hands is remarkable. In the future, the fusion of automation systems and industrial robots with IoT and AI will accelerate, and demand for mechatronics equipment will increase.

1. IoT / AI technology that complements automation and industrial robots

Automated systems and industrial robots play a major role in producing products. For example, an automated system can produce stable products of the same quality for a long time. Industrial robots can perform delicate work stably. It is very important nowadays when the labor shortage becomes serious. However, these are mechanical systems that do the job reliably. There are many tasks left in the factory that cannot be left to robots and can only be done by humans. Fusion of automation systems and industrial robots with IoT and AI technology is drawing attention as a way to solve this problem.

2. From automation to autonomy with IoT technology

IoT is an acronym for Internet of Things and is translated as the Internet of Things. A system in which all devices are connected to the network via a server, and each device communicates and controls autonomously. The introduction of IoT makes it easier to understand the current situation (visualization). For example, we constantly measure the operating status of machines and robots, and share and centralize information via the Internet. This makes it easier to find work that becomes a bottleneck, and to compare productivity differences between processes to lead to improvement activities. Also, in a factory that consumes a lot of power, it is possible to accurately understand the operating status and improve power efficiency.