# Adaptive Model Output Following Control for a Networked Thermostat +
## 2 Networked Thermostat System  
As shown in Figures 1 and 2, the networked thermostat system consists of two computers connected to the network, a PCL-812 PG board, a PCI-1760U board, a thermostat, a Peltier device, a temperature sensor, and a signal conditioning board. The thermostat temperature is collected and sent to PC1 by PC2. Based on the proposed method, PC1 returns the control outputs over the network. PC2 commands PCI-1760U to produce PWM according to the control output. The Peltier device will cool the thermostat as desired. The signal conditioning board is to amplify the voltage output of the temperature sensor and provides enough power for the Peltier device. Details are shown as follows:1. Thermostat: It is a container that ensures the temperature of the liquid flowing out is always the same as desired. While flowing from one side to another side, the liquid will be cooled by the Peltier device.
2. Temperature Sensor: LM35 Precision Centigrade Temperature Sensor is used to collect the temperature of the thermostat, whose voltage output increases linearly with the temperature. It is equipped at the side where liquid flows out. Its voltage output range 0-1 V corresponds to the temperature range 0-100 \({}^{\circ}\)C, and the measurement error is \(\pm\frac{1}{4}\) \({}^{\circ}\)C.
3. Peltier device: As shown in Figure 3, the Peltier device consists of a Peltier, a copper pipe, and two fans. The working voltage of the Peltier is 12 V. When current flows through the Peltier, the temperature at the endothermic side will decrease, and the other side radiates energy into the air. Its endothermic side is close to the thermostat. To improve the cooling ability, the fans and copper pipe is used to decrease the temperature on the radiation side. In this paper, the Peltier is controlled by pulse width modulation (PWM) produced by the PCI-1760U board.
4. PC1: It is used to receive the temperature of the thermostat through the network, run the proposed algorithm, and then return the result through the network.
5. PC2: This PC receives data sent by the remote computer PC1 over the network, and outputs the PWM wave to control the PCI-1760U board based on the proposed method.  
Figure 1: Experimental system.  
Figure 3: The configuration of the Peltier device.  
Figure 2: Thermostat system.  
Further, it commands the PCL-812 PG board to sample the voltage amplified by the signal conditioning board and send it over the network to the remote computer, PC1. (6) Signal conditioning board: In order to improve the precision of temperature, the voltage output of the temperature sensor is amplified from 0-1 to 0-5 V. Because the power provided by the PCI-1760U board is not enough for the Peltier, the PWM amplitude is converted from 5 to 12 V by the signal conditioning board. (7) PCL-812 PG board: It is inserted in PC2 and used to collect the temperature information from the signal conditioning board by a 12-bit analog-to-digital converter. Its voltage input range is 0-5 V. (8) PCI-1760U board: It can produce PWM used to control the thermostat temperature. Its voltage is 5 V and the period is set to 10 ms. (9) Network system: It is designed based on a network platform HORB based on the Java programming language. On this platform, a server is designed to manage tasks from local and remote terminals. This platform packets all the communication protocols, primary data processing, and remote function call. The only thing for the two PCs is to provide their IP addresses and tasks to the server at the beginning of the experiments.