There is a set of methods for a cloud on sky detection. The common passive examination of cloud presence is realized with digital post-processing of picture that was taken with a device that enables full-sky photography. As the camera is set in automatic mode the results of examinations depends on lighting conditions. Therefore up-today critical real-time applications are supported with laser or microwave devices that generate specific probing beams. The common feature of the mentioned devices is the high cost of equipment. Thus, the development of a sensing device that consists of standard modules and is intended for real-time measurements of the movement of clouds at skyline has been initiated. Proposed sensing device construction bases on a matrix of photodiodes integrated in the VEML6040 chip. The measurement results of the VEML6040 are analyzed with camera pictures. Obtained results show that filtered first derivative of ratio of blue to whole spectrum signal can be used to set proper thresholds that generate automatically signal of cloud movement detection.
The common examinations of distant objects colors are realized with digital post processing of picture. Therefore, results of examinations are delayed. Consequently, real-time measurements of medium distance objects color taking place on the skyline have been examined. The medium distant objects that are under investigations are a different type of skyscrapers positioned at distant from 1 km to 3 km. Examinations were performed at the same time with two types of color sensors. These sensors are TCS3200 and VEML4060, they differ in dimensions, photonics characteristics and data transmission type. Therefore, to carry out the examinations, a standalone measurement system based on Nucleo64 board has been programmed. The data sampling ratio was 250/s. Sensors calibration was performed with the laboratory set-up consist of the specialized light sources, monochromator, fiber optic light divider and optical power meter. During medium-distant objects color examinations sensors were connected with monocular. Mentioned objects optical spectra characteristics were referred to data obtained with spectrophotometer use. Obtained results pointed that the use of an optoelectronic color sensor and a commonly available optical system with a fixed focal lens enables real-time measurements of objects’ colors located on the skyline. The VEML6040 sensor shows better agreement than TCS3200 with spectrometric characteristics of distant objects.
There is a set of sensing devices for a cloud on sky detection. The common passive examinations of cloud presence are realized with digital post processing of picture that was taken with fish eye lenses. Therefore, results of examinations are delayed and information at skyline is degraded. The common examinations include also thermal image analysis or the active laser distant sensors adaptations. The common feature of these sensors is the high cost of equipment. Thus, sensing device constructions for real-time measurements of clouds taking place on the skyline have been examined. Examinations were performed at the same time with two sensing devices that include two different optical channels. The first sensing device, used as a laboratory reference, consists of two spectrometers Maya 2000 pro while mechanic module consists of a plate with large core optical fiber adapter and fiber optic collimator adapter. These adapters are used to fix collimator and an optical fiber that is connected to a proper spectrometer. The examination results enable to point relation of variation of cloud cover factor as variation in semi-stable band 440 nm and variation in an unstable band that extends to longer than 550 nm wavelengths. Therefore, the second device, aimed as a cost effective consist of two optoelectronic sensors type BH1750 and OPT101 that are connected by a mechanical adapter that includes optical filters to binoculars. These optical filters are 440 nm band pass and 550 nm long pass. The data obtained of examinations show that the second construction may be a base for further development of data processing algorithms for passive sensing device for a cloud on the skyline detection.
This paper presents the concept of a non-invasive method to determine the technical state of passenger car wheel rims. The method consists of a series of vibration and dimension measurement on a rim mounted in a diagnostic station. The measurements are taken on four positions of the rim of rotation versus constant excitation point angular position. The wheel rim’s natural frequencies distribution versus time and rotation angle are examined as diagnostic tool of rim fit for use classification from materials fatigue point of view. These characteristics are also inspected to determine the condition of joints of rim elements and to identify the cracks or loss of integrity in the wheel rim structure. The wheel rim dimensions as a series of specific diameters are examined for wheel rim radial run-out and for axial run-out. The proposed method was evaluated for a new and worn out rims. Performed experiments show that the natural frequency values of rim, the damping factor of natural rim vibration and rim diameters course grouped in a spider chart allows an effective visual classification of car rim fit for use.
Modern rims and wheels are tested at the design and production stages. Tests can be performed in laboratory conditions and on the ride. In the laboratory, complex and costly equipment is used, as for example wheel balancers and impact testers. Modern wheel balancers are equipped with electronic and electro-mechanical units that enable touch-less measurement of dimensions, including precision measurement of radial and lateral wheel run-out, automatic positioning and application of the counterweights, and vehicle wheel set monitoring - tread wear, drift angles and run-out unbalance. Those tests are performed by on-wheel axis measurements with laser distance meters. The impact tester enables dropping of weights from a defined height onto a wheel. Test criteria are the loss of pressure of the tire and generation of cracks in the wheel without direct impact of the falling weights.
In the present paper, a set up composed of three accelerometers, a temperature sensor and a pressure sensor is examined as the base of a wheel tester. The sensor set-up configuration, on-line diagnostic and signal transmission are discussed.