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 250 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 gravity for vehicle. The result of research discovered to the performance of center of mass tester was activated following to test conditions. Furthermore the position of the horizontal of center of gravity depends on the weight distribution at horizontal axis and an increasing of mass under non-uniform along the longitudinal and horizontal axis. In term of the position of the longitudinal of center of gravity the weight distribution at longitudinal axis and an increasing of mass rate are points. Otherwise the weight distribution at longitudinal axis and an increasing of mass are effect to the position of the vertical of center of gravity.

The aim of this research is to study the varieties of weight density distribution affect to the center of mass and vehicle stability. The weight density distribution tester was designed and changed the position of mass. Base on the center of mass is main points of vehicle stability. On the other hand FMCSA standard was applied to field test for considering of the brake performance and vehicle stability. The results of research discovered to the mass distribution on horizontal plane and fixed position Y1 are absolutely influence under an increasing 50 kilograms of mass condition. For the mass distribution on longitudinal plane and fixed position Z2 and Z3 are affected to the increasing of mass 100 and 150 kilograms respectively. Otherwise under an increasing of mass 200 and 250 kilograms there is non-influence to the weight density distribution. In term of the braking performance it’s depends on the lateral mass distribution especially the center position of mass installed on longitudinal and horizontal plane and close up on the front axle (Y2). For the vehicle stability results the position (Y2) is the highest influence for yaw rate and sideslip. Otherwise the position (Y3) or the position of mass installed on longitudinal plane and nearly at the left wheel on the rear axle. Additionally wheel lock-up condition was appeared on the front axle only. Because the behavior of the weight distribution on front axle was decreased lead to mass distribution on longitudinal plane.

This paper presents a CMOS voltage reference design which is widely used in electronic circuits both analog and digital circuits. In the conventional a CMOS voltage reference circuit design composed of several MOS transistors and complicated circuits the output voltage cannot be adjusted to any levels. Therefore in this paper proposed the CMOS voltage reference circuit design technique based on a new current combination circuit which it was reduced number of MOS transistors and the proposed circuit is able to operate without complex startup circuit. The performance of the proposed circuit is confirmed through PSPICE simulation results the circuit can be operated with supply voltage varies from 2V to 4V the output voltage reference is about 231 2mV at wide temperature range of -80 to 120 it has very low temperature coefficient of about 37.65 ppm/ and a total power dissipation of 7.37 W

This paper presents compare results performance between two conventional controllers for bicycle robot. The bicycle speed control system was a highly nonlinear model multivariable and absolutely unstable. It has used for testing various design control techniques for low power. The objectives of this paper had to developed speed control which derived the mechanic model and experiment. Controllers are Proportional-Integral-Derivatives (PID) and on-off dynamic control. The dynamic system which also includes not stable friction effects the linear zed system model is used as a basis for the design to apply to speed. Computer simulation and experiment have been done controller are capable to control output speed wheel control system successfully. The results show PID controller better then on-off dynamic controller.