K-P Ha’s research while affiliated with Seoul National University and other places

Dual mass flywheel (DMF) systems are used in many modern vehicles, owing to the well-known positive effects on vehicle drivability and fuel consumption. It is very important to measure the angular displacement of the DMF for the understanding of the characteristics of the DMF. This paper will discuss the development of the displacement measuring system for the DMF based on the principle of the linear variable differential transformer (LVDT), which can be installed in a real vehicle. It consists of a sensor node, power node, and BluetoothTM node, and transmits the displacement data by Bluetooth technology. A resistance temperature detector (RTD) was used to check the temperature of the DMF, and transmits the temperature data using Bluetooth technology. The developed displacement measuring system for the DMF shows good linearity and temperature compensation was conducted. It is installed in an in-line four-cylinder engine vehicle, and is successfully used to measure the displacement of DMF.

The engines in vehicles today are smaller in size and lighter in weight but are still required to produce high output power. These characteristics have been found to induce thermal problems in the engine. In solving this thermal problem, temperature measurement in the piston of the engine plays an important role. However, owing to the environment of the piston, it is difficult to measure the temperature in the piston. Thus, developing a method to measure the temperature of the piston is currently an important research topic. This paper presents a piston temperature telemetry system that was developed using Bluetooth. This system is advantageous in that it makes it possible to measure multipiston temperature using a Bluetooth wireless network, which is an area that has yet to be investigated in more depth. The telemetry system is composed of the piston part and the data acquisition part. To evaluate the performance of the telemetry system, experiments were conducted using a 2359 cm(3) DOHC engine produced by the Hyundai Motor Company. The experimental results show that the piston telemetry system is applicable to real commercial engines for measuring piston temperature.

Torque is one of the key factors in describing engine performance. It is distributed to various parts of the vehicle such as the valvetrain, generator, and water pump. However, the exact torque delivered to each part cannot be determined. The first step to a full understanding of torque distribution is direct measurement of engine output torque. This paper considers the development of a disc-type torque meter that can be installed in a real vehicle. It uses the elastic deformation of a torque sensor which replaces the driveplate. It consists of a strain node, a power node, and a telemetry node, and transmits the torque signal by Bluetooth technology. The developed disc-type torque meter has good linearity and thermostability. It was installed in an in-line four-cylinder engine vehicle, and successfully measured the engine output torque.