Low-cost Infrared Sensors Research Articles

Development of personal comfort model and its use in the control of air conditioner

The accurate identification of the real-time thermal state of personnel working indoors has been the focus of researchers. In this study, a detailed examination of the entire process of developing a personal comfort model, from theory to practice, is conducted. In particular, the subject of this investigation is a smart air conditioner capable of predicting thermal sensation based on an infrared (IR) sensor that measures the skin temperature of personnel and then implements automatic control. Random forest algorithm was employed to establish a thermal sensation prediction model, which accepts skin and air temperatures as input parameters. The model achieves a high prediction accuracy value of 0.84. Given the measurement errors of low-cost IR sensors, a simulated temperature measurement experiment based on the manikin was conducted, and an error calibration method based on multiple linear regression was developed through the experiment. 30 subjects participated in another prototype test experiment, which proved that the air conditioner can accomplish effective automatic control based on the prediction of thermal sensation, avoid the occurrence of extreme temperatures, and ensure the thermal comfort of personnel. The possible causes of remaining problems and potential improvement schemes are discussed in detail.

Water Stress Index Detection Using a Low-Cost Infrared Sensor and Excess Green Image Processing.

Precision Irrigation (PI) is a promising technique for monitoring and controlling water use that allows for meeting crop water requirements based on site-specific data. However, implementing the PI needs precise data on water evapotranspiration. The detection and monitoring of crop water stress can be achieved by several methods, one of the most interesting being the use of infra-red (IR) thermometry combined with the estimate of the Crop Water Stress Index (CWSI). However, conventional IR equipment is expensive, so the objective of this paper is to present the development of a new low-cost water stress detection system using TL indices obtained by crossing the responses of infrared sensors with image processing. The results demonstrated that it is possible to use low-cost IR sensors with a directional Field of Vision (FoV) to measure plant temperature, generate thermal maps, and identify water stress conditions. The Leaf Temperature Maps, generated by the IR sensor readings of the plant segmentation in the RGB image, were validated by thermal images. Furthermore, the estimated CWSI is consistent with the literature results.

Evaluating petrol engine oil deterioration through oxidation and nitration parameters by low-cost IR sensor

For the proper working of the internal combustion engine, engine oil plays a significant role. The performance of the engine is greatly affected by oil that has degenerated. In order to determine the optimal gap between oil changes, it is crucial to measure the deterioration in the engine oil. Multiple parameters like oxidation, nitration, viscosity and so on are brought into use. One of the methods used to quantify the deterioration in the engine oil is the Fourier Transform Infrared (FTIR) spectroscopy. The main parameters of the engine oil are distinguished by this method by utilizing Infrared (IR) absorption at different bandwidths. The two significant parameters in engine oil deterioration are oxidation and nitration. However, the limitation of the FTIR method is that it is more expensive and since it uses huge machinery, it requires a lot of area. Hence, the use of this method is not possible in the field area due to the need for space. It is this major limitation that is the motivation for proposing an inexpensive, yet handy system, using an IR sensor set up, in this paper. This system is used for measuring the transmittance of engine oil that has degenerated. For this paper, we collected random samples at various times from service stations that were specifically authorized. These samples were used in experiments based on the FTIR spectroscopy and UV spectrophotometer and the results were compared using the IR sensor setup. Investigation of the experimental results showed that monitoring oil transmittance using an IR sensor setup is possible, and a robust relationship between oxidation and nitration and the transmittance of the oil was observed. Moreover, a pattern of deterioration for a specific engine oil (SAE 5W30) which is utilized for passenger cars and light duty vehicles was also established.

A Localization Method Based on Map-Matching and Particle Swarm Optimization

This paper presents a novel localization method for small mobile robots. The proposed technique is especially designed for the [email protected], a new robotic competition which is started in Lisbon in 2011. The real-time localization technique resorts to low-cost infra-red sensors, a map-matching method and an Extended Kalman Filter (EKF) to create a pose tracking system that performs well. The sensor information is continuously updated in time and space according to the expected motion of the robot. Then, the information is incorporated into the map-matching optimization in order to increase the amount of sensor information that is available at each moment. In addition, the Particle Swarm Optimization (PSO) relocates the robot when the map-matching error is high, meaning that the map-matching is unreliable and the robot gets lost. The experiments presented in this paper prove the ability and accuracy of the presented technique to locate small mobile robots for this competition. Extensive results show that the proposed method presents an interesting localization capability for robots equipped with a limited amount of sensors, but also less reliable sensors.

New, low cost infra-red sensor has electronics integrated in the cable

New, low cost infra-red sensor has electronics integrated in the cable

Using infrared sensors for distance measurement in mobile robots

The amplitude response of infrared (IR) sensors based on reflected amplitude of the surrounding objects is non-linear and depends on the reflectance characteristics of the object surface. As a result, the main use of IR sensors in robotics is for obstacle avoidance. Nevertheless, their inherently fast response is very attractive for enhancing the real-time operation of a mobile robot in, for instance, map building tasks. Thus, it seems that the development of new low-cost IR sensors able to accurately measure distances with reduced response times is worth researching. In this paper, a new IR sensor based on the light intensity back-scattered from objects and able to measure distances of up to 1 m is described. Also, the sensor model is described and the expected errors in distance estimates are analysed and modelled. Finally, the experimental results obtained are discussed.

429 Detecting Incipient Water Stress in Buffalograss and Kentucky Bluegrass through Foliage Temperature using Lowcost Infrared Sensors

Infrared sensors were used to quantify canopy temperature and thus detect differences in incipient water stress between a cool-season grass [Kentucky bluegrass (KBG) (Poa pratensis)] and a warm-season grass [buffalograss (BG) (Buchloe dactyloides)]. The infrared sensors, connected to a datalogger, measured average hourly leaf–air temperatures (TL–TA) 1 m above eight replicate plots of Kentucky bluegrass and eight replicate plots of buffalograss. Air temperature and relative humidity from a nearby weather station were used to calculate the average hourly vapor pressure deficit (VPD). In late July, we ceased irrigating and measured TL–TA and soil water content while allowing the turf to dry down for 5 weeks. Soil water content was measured with a neutron probe. Both species exhibited a significant relationship between TL–TA and VPD. As the VPD increased, TL–TA decreased in both species (KBG r2 = 0.73, BG r2 = 0.71) on the 2nd day after an irrigation during well-watered conditions. An artifact was created on the first day after an irrigation as a result of excessive surface evaporation. KBG and BG were similar under well-watered conditions. KBG had a higher TL–TA after 4 to 5 days without irrigation. By contrast, BG did not have a higher TL–TA until 25 to 30 days without irrigation. Part of BG's drought avoidance was extraction of soil water down to 0.9 m vs. 0.45 m for KBG.