Bing Ai

University of Texas at Austin | UT · Department of Computer Science

Time delay is a common phenomenon in robotic systems due to computational requirements and communication properties between or within high-level and low-level controllers as well as the physical constraints of the actuator and sensor. It is widely believed that delays are harmful for robotic systems in terms of stability and performance; however, w...

In the semiconductor manufacturing batch processes, each step is a complicated physiochemical batch process; generally it is difficult to perform measurements online or carry out the measurement for each run, and hence there will be delays in the feedback of the system. The effect of the delay on the stability of the system is an important issue wh...

One of the primary energy consumers in buildings are the Heating, Ventilation, and Air-Conditioning (HVAC) systems, which usually operate on a fixed schedule, i.e., running from early morning until late evening during the weekdays. This fixed operation schedule does not take the dynamics of occupancy level in the building into consideration, theref...

Semiconductor manufacturing industry has elevated cost in productions. Improvement of production efficiency is always an important goal for manufacturers. Because of the high capital costs associated with the process equipments, it is a common practice in today’s semiconductor manufacturing to have many different products and processes run on each...

In the semiconductor manufacturing batch processes, each step is a complicated physicochemical batch process; generally it is difficult to perform measurements on-line. The effect of the metrology delay on the stability of the system is an important issue needs to be understood. This paper investigates the stability of systems under exponentially w...

Run-to-run controllers based on the exponential weighted moving average (EWMA) statistic are probably the most frequently used for the quality control of certain semiconductor manufacturing process steps. The threaded-EWMA run-to-run control is an important stable control scheme. However, the process outputs will deviate largely in the first few ru...

In semiconductor manufacturing processes, mixed-products are usually fabricated on the same set of process tool with different recipes. Run-to-run controllers which based on the exponential weighted moving average (EWMA) statistic are probably the most frequently used in industry for the quality control of certain semiconductor manufacturing proces...

In semiconductor manufacturing processes, mixed-products are usually fabricated on the same set of process tool with different recipes. Run-to-run controllers which based on the exponential weighted moving average (EWMA) statistic are probably the most frequently used in industry for the quality control of certain semiconductor manufacturing proces...

The threaded-EWMA run-to-run control is an important stable control scheme. However, the process outputs will deviate largely in the first few runs of each cycle if the disturbance follows an IMA(1,1) series with deterministic linear drift/fault and the thread has a long break length. In this paper, we analyzed the output of the threaded-EWMA run-t...

Run-to-run(R2R) control is widely adopted in semiconductor manufacturing industries. Exponent weighted moving average(EWMA) is an important R2R algorithm. Discount factor is a major parameter of EWMA controller. Considering the high-mix characteristics of multi-product in practical manufacturing processes, we adopt the EWMA algorithm with time-vary...

A novel control approach which deals with two product process in semiconductor manufacturing industry is presented. It eatimates the patterned tool drift by the data acquired in the previous run. The patterned tool disturbance is obtained by combination of feed-forward and the feedback control for the consecutive runs. The output and AMSE (asymptot...

Semiconductor manufacturing industry has elevated cost in productions. Improvement of production efficiency is always an important goal for manufacturers. Run-to-run control has been widely used in batch manufacturing processes to reduce variations. Threaded exponentially weighted moving average (threaded-EWMA) run-to-run control is an important an...

Semiconductor manufacturing is an industry with high cost. Improvement of production efficiency is always an important goal for manufacturers. Run-to-run control has been widely used in batch manufacturing processes to reduce variations. Threaded EWMA run-to-run control is an important stable control scheme. In this paper mixed products are manufac...