จำนวน Repository ( 42 )
การออกแบบและพัฒนาชุดขับเคลื่อนในการทดสอบการชนรถจักรยานยนต์
A design and development of powertrain module crash test using with the motorcycle crash test is aim to create a special tool for automotive assessment and safety engineering based on the realistic test. In order to main system of power module tester is consisting of powertrain system using electrical motor transferring system using chains and gears and control direction system using dual rails respectively. Based on powertrain module tester performance crashing speed relative angle between target and distance before crash are regarded. Nevertheless the result of testing performance was conducted to statistic hypothesis test by Mean Absolute Deviation: MAD Standard Deviation: SD Mean Square Error: MSE Mean Absolute Percent Error: MAPE and Root Mean Square Error: RMSE. The results of this approach discovered that the crashing speed was the highest error with 96% and the lowest was distance before crash. Furthermore it was corresponding to the statistic hypothesis test. However the result of the error was influence of the rails distance which limit by funding. In case of crash energy the mean of energy was appeared on 10.978 J. Whereas the tendency of variable was similar to polynomial equation.
ออกแบบและสร้างหุ่นทดสอบการชนของรถจักรยานยนต์ภายใต้สัดส่วนโครงสร้างของคนไทย
The aim of this research is to design a prototype of a male dummy chest for motorcycle crash tests. The primary criteria discussed in this study are based on the unique features of Thai ergonomic body sizes with an age range of the highest fatal rate and the fundamental design of the Hybrid III 50th percentile male crash test dummy. A comprehensive experimental study of crash behavior of the prototype undergoing axial compressive loading is performed using the mutual procedure of cadaveric chest testing. For design criteria the largest chest deflection of 80 mm the maximum acceleration of 38.47g and the absorbed energy of 178.369 Joules are considered in the experiment. The obtained results show a good agreement with the experimental data of other researches in which the capability of the energy absorption depends on impact velocities. In addition the energy absorption capability of this prototype can accurately assess an injury level under AIS 3+. For this reason the first prototype of a male chest dummy is particularly suitable for an assessment of a lower serious injury level in a motorcycle crash test.
การทดสอบสมรรถนะของเครื่องขยายไอแบบสโครลสำหรับโรงไฟฟ้าโออาร์ซีขนาด 1 กิโลวัตต์
The ORC power plant is a promising technology to generate electricity from low-temperature heat sources. However implementation of the ORC for low capacity electricity generation is unattractive at the commercial level. Scroll compressors are massively produced to be used in refrigeration and air-conditioning applications. Using a scroll compressor in reverse as an expander can reduce the investment cost of low-capacity ORC power plants. In this study 2 scroll compressors that are available in the automotive air-conditioning market of Thailand were modified and used as the expander of a 1 kW ORC power plant. The performances of these 2 scrolls were compared and the plant performance was investigated. A heat source temperature from 100°C to 150°C was supplied to the plant. It was found that the gross power is higher by 18-35% for the larger expander (110 cc/rev) than for the smaller expander (85.7 cc/rev). The larger one provides the isentropic efficiency of 37-76% and the gross power of 806-1926 W. In addition the effects of check valve installation were examined and compared with those of the tests without check valve installation. It was revealed that the isentropic efficiency increases by 18% while the gross power decreases by 4-22% when the check valve was installed.
การศึกษาจุดศูนย์กลางมวลและสัดส่วนการเบรกที่ส่งผลกระทบต่อเสถียรภาพการบังคับยานยนต์ โครงการวิจัยย่อยที่ 1 เครื่องทดสอบจุดศูนย์กลางมวลสำหรับรถยนต์
The aim of this research is to create the center of mass testing machine for vehicles with maximum mass 3000 kilograms. By the performance of this machine is able to determine the center of mass 3 axis by horizontal longitudinal and vertical. On the other hand the verities of mass from 50 to 100 kilograms and the several of weight distribution at horizontal and longitudinal are applied to the condition of testing for reasonable to the position of the center of mass. The result of research discovered to the performance of center of mass tester was activated following to test conditions. Furthermore the weight distribution at longitudinal was the highest effect to the horizontal center of mass. By the way the value of weight distribution at horizontal is more effects to the longitudinal center of mass. Moreover increasing of mass was impact to the vertical center of mass and it’s independent to the position of weight distribution.
การเปรียบเทียบประสิทธิภาพของตัวสถิติทดสอบสำหรับการทดสอบ ความแตกต่างของค่าเฉลี่ยระหว่างประชากร 2 กลุ่มที่อิสระกัน
The objectives of this study were to calculate the probability of type I error power of a test and to compare the performance of three test statistics: Z Student’s t and Welch’s t. Including the recommending the appropriate test statistic. Classification of the population according to five distribution. The ratios of mean group 1 per group 2 were three levels. The ratios of variance group 1 per group 2 were three levels. The sample sizes of two populations were nine sizes. The significance levels that to study were 0.01 and 0.05. The data were simulated by using SAS programming with 1000 replicates. Results of the research were Z test statistic could control the probability of type I error and had higher power of a test than other test statistics but this test is necessary to know the variances of the two groups. Therefore it was appropriate to apply the other test statistics i.e. Student’s t or Welch’s t. If the variances of the two groups were equal Student’s t was a more appropriate test statistic than Welch’s t. But if the variances of the two groups were not equal Welch’s t was a more appropriate. When both sample sizes were large and the population variances were equal we could use any tests since there is no difference in the performance.