 Hello, I am Milka Jagle working as Assistant Professor in Department of Mechanical Engineering Vulture Institute of Technology, Solapur. Today, we are going to learn about various mechatronics system. Let's start. Learning Outcome. At the end of this session, learners will be able to explain the working of mechatronics systems. So, let's see what is a typical mechatronic system. A mechatronic system consists of mechanical systems, electrical systems and information technology. A typical mechatronic system such as humanoid robot consists of mechanical elements, sensors, actuators, controllers, signal conditioning devices, computer and software interfacing and power devices. So, let's start with an example of a mechatronics system that is humanoid robot. Humanoid robot system is more complex and intelligent mechatronic systems. It involves servomotors, sensors, controllers, electronics, electrical devices and embedded actuators with artificial intelligence capabilities. The three major elements of humanoid robot are, first is sensors, second is actuators and third is planning and control. So, the figure shows the schematic sketch of humanoid robot in which you can see the various sensors over here that is force sensors, camera, processing unit, antenna, central processing unit, battery, receiver and various processing units. So, let's see the first sensors. So, there are two types of sensors that is proprioceptive sensors and exteroceptive sensors. So, let's see what is the first type of sensor that is proprioceptive sensors. They sense the position, orientation and speed of the humanoid body and the various joints. The second type of sensor is exteroceptive sensors. These sensors give the robot information about surrounding environment, allowing the robot to interact with the world through vision and sound. So next, that is actuators. The humanoid robots are constructed in such a way that they mimic the human activities or the motion human body does. So, the same is given to the humanoid robot. So, these actuators perform the functions of muscles and joints. So, as the moment of robot has to be human like using leg locomotions, dynamic balancing during work is very important. So, the humanoid robot should balance itself while it does the activity of walking. The planning and control focuses on self-collision, detection, path planning and obstacle, avoidance to allow humanoid to move in complex environment. The humanoid robot is an autonomous robot because it can adapt to changes in its environment on its own and continue to reach its goal. So, let's see the features of humanoid robot. The first feature is self-maintainance. Second is autonomous learning. Third is avoidance of situations harmful to people, property and itself. And the fourth is safe interaction with human. So, let's see the next type of mechatronic system that is automatic camera. Automatic camera has an automatic focusing and exposure. For activating the system, when the switch is operated and the camera is pointed at the object to be photographed, the microprocessor takes the output from the range sensor and sends an output to the lens position to adjust the focusing. The lens position is feedback to the microprocessor so that the feedback signal can be used to modify the lens position according to the input from the range sensor. The light sensor gives an input to the microprocessor which then gives output to the output to determine if the photographer has selected the shutter control mode rather than aperture control mode. The time for which the shutter will be open. So, the figure shows the diagram for automatic camera. It has many actuators, it has a motor drive and most of the things are done automatically without any manual interference. So, this figure also shows the figure for automatic camera. So, the next type of application that we are discussing today is washing machine control. So, washing machine uses a microcontroller pulse width modulation that is PWM feature of microcontroller controls the motor speed which is one of the important component of the washing machine control. PWM output is fed to the driver circuit and then to the motor in two different directions that is forward and reverse direction. The door sensors, keypad, pressure sensor are interfaced to the microcontroller. So, let us see the process of microcontroller. Here we can see the washing machine is an example in which each and every activity has to be done in the sequence or in the decided order. So, that is why washing machine is known as sequential control system. In this system, number of operations or events have to be carried out in order or in the correct sequence. The various events of washing machine are shown in the figure. Here the first step in the washing machine is a pre-wash cycle. So, in this for this step in this pre-wash cycle the cloths in the drum are given a wash in the cold water and the inlet wall has to open water inlet has to be switched on so that the water in the drum reaches a certain level and this water level is sensed by water level indicator and the output is given to the microprocessor and it stops the water inlet when the water up to the decided level is reached. After the water is given into the drum in this pre-wash cycle as the outlet wall is closed now the motor is driven and the drum starts rotating in the direction which is fed. The outlet wall is open so that the water in the drum is given out and in this way the pre-wash cycle is completed. Second step that is main wash cycle the cloths are washed in the hot water. For this step first the inlet wall has to be open to get the water inside. So when the water in the drum reaches up to the level which we require the water inlet is closed by one of the sensor and when the water level is reached inlet wall is closed and after that the heater starts to heat the water in the drum. So when the temperature of water is reached up to the preset value then the heater offs and the sensors, sensors the temperature and drum starts rotating and wash cycle is completed. So next step that is rinse cycle in this the cloths are rinsed with cold number of times. In this third step after in the cold water continuous rotating of drum in the reverse and forward direction is done so that the cloths are rinsed properly and in the last step that is spinning cycle drum rotates with a higher speed than all the three steps above because the water has to be removed from the cloths. So in this way the automatic sensations of the various parameters is done and the washing action is completed. These are the references W Bolton book and a book Shetty and Coke and book Mahalik that is principal concepts and applications by Tata McGraw-Hills. Thank you.