Unggul Wasiwitono

Anti-windup compensator design considering behavior of controller state

In this paper, we propose a design method of a static anti-windup compensator for good tracking performance. In the previous design methods for the anti-windup compensator, the controller and the plant states have not been considered directly in the ℒ2 gain performance index. Considering that the windup phenomena are caused by the controller and the plant having badly damped or unstable mode, we introduce a new ℒ2 gain performance index that contains the controller state and the plant state. Good tracking performance is obtained by tuning the weights on the two states of the performance index, which is demonstrated by two examples.

Effect of feedback measurement on LQG control for Low Bandwidth Active Suspension system

Conventional suspension system is now considered to have an unsatisfying limitation in terms of all-condition performance. Selection of certain spring and damper value is preferred to fail giving the admired response. Active suspension has been studied intensively in many years to diminish this problem. Low Bandwidth Active Suspension (LBAS) is shown to be more competitive to high bandwidth one when energy and cost aspects are taken into account. In this study, the effect of the measurement which is used for feedback in the LQG control of LBAS performance is analyzed. The achievable performance of the LBAS is shown by means of carpet plot and the simulation is conducted considering the road disturbance as a stationary random process.

ACTUATOR POWER CONSUMPTION OF ACTIVE SUSPENSION SYSTEM WITH OVERRIDE CONTROL STRATEGY

The main function of the vehicle suspension is to improve ride and handling performance. In vehicle active suspension, better ride comfort is usually required larger control input and larger suspension deflection. However, the actuator that deliver the control signal have a limitation which is commonly known as actuator saturation. There is also a structural constraint that limits the suspension deflection. In this study, an alternative approach to the vehicle active suspension system is proposed. In this approach, some separation in the controller such that one part is devoted to achieve nominal performance and the other part is devoted to constraint handling is performed. In addition, the actuator power consumption of the proposed control strategy is further investigated numerically. The simulation results show that the proposed control strategy can manage the trade-off between performance and the actuator power consumption.

Influence of Spring Ratio on Variable Stiffness and Damping Suspension System Performance

The variable stiffness and damping (VSVD) suspension system offers an interesting option to improve driver comfort in an energy efficient way. The aim of this study is to analyze the influence of the spring ratio on the VSVD. The realization of the VSVD is obtained by the application of variable damping with magnetorheological (MR) damper. In this study, the nonlinear damping force characteristic of the MR damper is modeled with the Bouc-Wen model and the road disturbance is modeled by a stationary random process with road displacement power spectral density. It is shown from simulation that VSVD has a potential benefit in improving performance of vehicle suspension.

Analisis Pengaruh Perubahan Geometri Suspensi terhadap Dinamika Getaran Sepeda Motor

Sistem suspensi mempunyai peranan penting pada kendaraan sebagai penunjang kenyamanan dan keselamatan berkendara. Berbagai usaha telah dilakukan untuk meningkatkan performa sistem suspensi, salah satunya dengan menggunakan sistem suspensi aktif. Kebutuhan terhadap energi yang sangat besar pada sistem suspensi aktif menginspirasi banyak peneliti untuk meningkatkan performa sistem suspensi dengan kebutuhan energi yang tidak terlalu besar. Selain pemilihan pegas dan peredam yang sesuai, geometri sistem suspensi juga mempunyai pengaruh yang signifikan terhadap kinematika dan dinamika sistem suspensi. Sehingga salah satu usaha untuk meningkatkan performa sistem suspensi adalah dengan memanipulasi geometri sistem suspensi atau yang dikenal sebagai variable geometry suspension. Pada penelitian ini akan dianalisis pengaruh perubahan geometri terhadap dinamika getaran sistem suspensi roda belakang sepeda motor. Perubahan geometri yang dianalisis adalah perubahan posisi bottom mounting suspensi dan panjang link untuk konstanta kekakuan pegas yang juga divariasikan. Dari hasil simulasi diperoleh bahwasanya apabila semakin dekat jarak bottom mounting suspensi dengan titik mounting pada connecting rod, maka semakin kecil respon percepatan yang diperoleh. Jika link semakin panjang, maka semakin kecil pula nilai respon percepatan yang diperoleh. Dan apabila semakin kecil kekakuan pegas yang digunakan, semakin kecil respon percepatan yang diperoleh. Selain itu, berdasarkan hasil simulasi, dibandingkan dengan suspensi Pro-Link, sistem suspensi yang dipelajari pada penelitian ini memberikan respon percepatan yang lebih baik.

Constrained ℋ∞ control for low bandwidth active suspensions

Low Bandwidth Active Suspension (LBAS) is shown to be more competitive to High Bandwidth Active Suspension (HBAS) when energy and cost aspects are taken into account. In this paper, the constrained ℋ∞ control scheme is applied for LBAS system. The ℋ∞ performance is used to measure ride comfort while the concept of reachable set in a state-space ellipsoid defined by a quadratic storage function is used to capture the time domain constraint that representing the requirements for road holding, suspension deflection limitation and actuator saturation. Then, the control problem is derived in the framework of Linear Matrix Inequality (LMI) optimization. The simulation is conducted considering the road disturbance as a stationary random process. The achievable performance of LBAS is analyzed for different values of bandwidth and damping ratio.

Steady-State Cornering Modeling and Analysis of Three-Wheel Narrow Vehicle

Electric mobility seems to be an innovative alternative to future urban transport. In this study, a steady-state cornering model of a three-wheel narrow electric vehicle is derived. The steady-state cornering analysis is conducted by varying the location of the vehicle center of gravity, speed and tilt angle. From this analysis, the center of gravity location and tilt angle that gives better cornering characteristics can be obtained. Therefore, this analysis helps and can be used as starting point to design the chassis and the tilting control system of the three-wheel narrow electric vehicle.