IMPROVED MOTION CONTROL SYSTEM ON ELEVATOR LANDING AND RE-LEVELING by Tou Wai Kei Thesis Supervisor: Associated Professor Vai Mang I Electrical and Electronics Engineering The motion of an elevator during landing and re-leveling is critical to safety, ride comfort and efficiency. Direct landing method has been introduced since the last decade with the deployment of computerized elevator controller. In contrast to traditional landing method, direct landing utilized close-loop control to the elevator position. This can greatly reduce landing time and improve land position accuracy. However, good direct landing control relies on the use of high resolution absolute position sensor, which is expensive to install and maintain. In the first part of this thesis, a study to the elevator positioning system was given. A new algorithm is then introduced to perform direct landing with the use of existing elevator components. The algorithm is tested in simulation, laboratory experiment and site experiment. With the experiment result, further improvement and fine-tuning of this new algorithm were also given. The second part of this thesis is focus on elevator re-leveling. While elevator is loading and un-loading at floor level, the elevator cabin position may fluctuate due to loading weight changes. For high-rise building, the difference between floor level and elevator platform could be more than 10mm. This is dangerous to passenger that who did not notice the level difference. Since the position of the elevator cabin cannot be measured directly by the system with existing component, a new device is designed to perform the absolute position measurement between floor level and elevator cabin. In order to reduce cost of modification, interruption infrared (IR) sensors are used in the new design to work as a low resolution linear image sensor. This sensor is then fusion with a low cost MEMS accelerometer to enhance the position resolution and respond time. Kalman filter is used to perform data filtering and data fusion to both sensors reading. Simulation and experiment has been done to confirm the performance of the new device. Yet, study on the criteria of using re-leveling is also given.