As the terms sounds, a semi-automatic system works half manually and half automatically. In a car which runs with semi-automatic gear shift system requires the driver to make gear change by themselves, like with a manual gearbox but it keeps us away from the tussle that we face with the clutch, though it is automatic in the term it doesn’t mean we can simply rely upon computer and lean on the seats.
Do you know what makes semi-automatic transmission differs from a manual transmission? instead of cables and pipes running from the transmission to the driver so that they can affect the gear change, we have actuators and computers doing all that tussle for you. Apart from the fully automatic system semi have some sort of appealing points which every driver focus on, it is when the car makes a sudden heavy braking. This system provides the advantages of manual gear and the smoothness of fully automatic system as well.
The working of this system is as the power generated by the engine in the form of a turning input shaft, and, through the use of various gears, transfers it out where it can turn the wheels. In a regular manual transmission, the driver would control both the clutch and gear shifting by means of a pedal to engage and disengage the clutch, and a lever for gear change. Semi-automatic transmissions do away with this by replacing the gear lever with a set of actuators, and the clutch pedal with a hydraulic motor. A computer(sensors and processors )monitors and regulates various inputs, such as the vehicle speed, engine torque, accelerator pedal position, and more in order to determine when to do the gear change and in which direction. Comparing with the comforts of other systems semi-automatic systems will plummet down for it low durability and cost efficiency, it is prone to failure frequently and the cost of maintenance is higher, yet it is better choice for a normal computer.