Automatic control system consists of three major controllers, sensors and actuators, whose block diagram shown in Figure 1-1.

The controller action is required to achieve the control law. The controller can be a traditional control system calibration network, it can be complex computer control system.

The role of executive agencies is to change the state of the controlled object. Actuators can be a wide variety of power output devices, such as motors, hydraulic AK dynamic system, a series of measures can be taken against the accused objects, such as through comprehensive control multiple quantities to make the controlled object at a predetermined regularity run.

The sensor is to measure the effect of the state of the controlled object, and converts a physical quantity into easily handled. With the sensor will be able to know the actual state of the controlled object, and this state with the command, the comparison of the results by the controller to deal with, and then used to control the operation of the actuator, so that we can guarantee a good automatic control system After the operation, the state of the controlled object can be achieved Directive.

Instruction refers to the automatic control system that people want to accomplish, for the different control systems are different forms of instruction. Can be an electrical signal, the position of a handle, a piece of computer program, a set of data, can also be a combination of several forms of the above. But, anyway, eventually need to be converted into a physical reflection of the state of the controlled object.

Thermostat for temperature control system, the sensor is a temperature measuring means for measuring the temperature inside the temperature and the measured temperature value converted into a corresponding electrical signal. Actuator is temperature control device for controlling the temperature inside temperature. The controller in accordance with a predetermined rule, to control the temperature control device. For this system, the command is the value of the temperature inside the temperature you want to achieve, and accused the state of the object, but also the value of the temperature inside temperature. Specific system block diagram shown in Figure 1-2:

When the temperature inside temperature is 25 ℃, the instruction temperature is 80 ℃, the specific work of the system are: temperature measuring device measured the temperature inside temperature and temperature compared with the directive, the actual temperature is small, and therefore, control heating temperature control means is switched on, so that the temperature inside the temperature gradually increased to the instruction temperature and then disconnect the heater controller, the temperature inside the temperature will not rise. Thereafter, when the temperature is below the temperature inside 80 ℃, the controller will control the heater so that the temperature inside the temperature is maintained at the set temperature.

For unmanned vehicles, drive controller is a computer control system, it is an intelligent control system, and the basic data stored digital map, traffic regulations. Throttle actuator control means includes direction control means in such a brake control device, and the sensor includes (detecting road conditions around the vehicle) of the image sensor, a navigation system (amount of vehicle side direction, speed, position, acceleration, and other information) , engine condition sensor (measuring engine speed, temperature, fuel and other data), with its automatic control system block diagram shown in Figure 1-3.

When the input to the automatic control system from point A to point B driving instruction, car navigation systems to measure the current position, speed and other information, and plan a travel route based on the electronic map, the image sensor measuring road conditions, controlled by a computer drive system (controller) to issue the corresponding control commands to control the throttle actuator operated vehicles, direction, in the process of moving, engine condition detecting sensor is always working condition car engine, providing the basis for the control of the controller.Throughout the process of moving the image sensor to detect real-time road conditions also require the image transmitted to the drive control system to drive as A member of the same acceleration and deceleration, changing lanes, overtaking, braking and other operations.

From a broad perspective, the control device is the device used in the automatic control system. However, the habits, the controller controls the device by the automatic control theory and electronic technologies introduced in the course, refers to the sensors and actuators used in the automatic control system.