ABSTRACT
Compared to air, water and rail, road transportation is the commonest means of transport in Nigeria (Malik F.A., 2017). Technological advancements have led to the introduction of motor vehicles as means of mobility in road transportation. In Nigeria, there is a rapid increase in vehicle ownership causing an increase in the number of road traffic accidents (RTAs). Speed violation accounts for the highest percentage of causative factors of RTAs (NBS, 2018) thus, impacting negatively on the social, economic, human and health systems of the country leading to the enforcement of the use of speed limiters in commercial vehicles by the Federal Road Safety Commission (FRSC) of Nigeria. Hence the purpose of this work to develop a more robust variable speed control device which also monitors functioning parts of the vehicle.
This work was achieved by using electrical components to simulate the real life control inputs signals of the brake oil, engine oil and engine temperature of a Toyota corolla, 1993 model, manual transmission (MT) car and, then calibrating the outputs of an accelerometer – gyroscope circuit and an ultrasonic sensor as wheel alignment and tyre thread level control signals. These simulated control inputs were interconnected with the designed speed control system. The speed control system houses a microcontroller, AT89C52 which is the brain of the system. The microcontroller was programmed using ASSEMBLY LANGUAGE. The microcontroller monitors the simulated control inputs and responds by altering the signal voltage which changes to the desired speed. The system was also designed to send alert signals to an LED which blinks at a high frequency, a buzzer and a GSM module when a fault is detected and has an LCD which displays the current status of the fault(s) detected.
The work was tested by setting each of the control inputs to their fault state and the response of the system was observed and tabulated. The voltage signal as generated by the throttle position sensor (TPS) of Toyota corolla, 1993 model, manual transmission (MT) was simulated and connected to a DC motor for demonstration purpose. The change in the speed of the DC motor was also observed and noted in the table of results. The results of the tests performed were found to be satisfactory as the system gave the desired results. The designed system was developed as stand – alone device which can be interfaced with any brand of vehicle. Implementation of this work would bring about much safer highways and a healthier socioeconomic environment.
