Rui Song

Facial Expression Recognition with Fusion Features Extracted from Salient Facial Areas

In the pattern recognition domain, deep architectures are currently widely used and they have achieved fine results. However, these deep architectures make particular demands, especially in terms of their requirement for big datasets and GPU. Aiming to gain better results without deep networks, we propose a simplified algorithm framework using fusion features extracted from the salient areas of faces. Furthermore, the proposed algorithm has achieved a better result than some deep architectures. For extracting more effective features, this paper firstly defines the salient areas on the faces. This paper normalizes the salient areas of the same location in the faces to the same size; therefore, it can extracts more similar features from different subjects. LBP and HOG features are extracted from the salient areas, fusion features’ dimensions are reduced by Principal Component Analysis (PCA) and we apply several classifiers to classify the six basic expressions at once. This paper proposes a salient areas definitude method which uses peak expressions frames compared with neutral faces. This paper also proposes and applies the idea of normalizing the salient areas to align the specific areas which express the different expressions. As a result, the salient areas found from different subjects are the same size. In addition, the gamma correction method is firstly applied on LBP features in our algorithm framework which improves our recognition rates significantly. By applying this algorithm framework, our research has gained state-of-the-art performances on CK+ database and JAFFE database.

Design and experimental research on cantilever accelerometer based on fiber Bragg grating

Currently, an acceleration sensor based on fiber Bragg grating (FBG) has been widely used. A cantilever FBG accelerometer is designed. The simulation of this structure was implemented by finite element software (ANSYS) to analyze its sensing performance parameters. And then the optimized structure was produced and calibration experiments were conducted. On the basis of simulation, optical fiber is embedded in the inner tank of the vibrating mass, and Bragg grating is suspended above the cantilever structure, which can effectively avoid the phenomenon of center wavelength chirp or broadening, and greatly improve the sensitivity of the sensor. The experimental results show that the FBG accelerometer exhibits a sensitivity of 75u2009u2009pm/(m/s2) (100xa0Hz) and dynamic range of 60xa0dB. Its linearity error is <2.31% and repeatability error is <2.76%. And the resonant frequency is ∼125u2009u2009Hz. The simulation results match the experimental results to demonstrate the good performance of FBG accelerometer, which is expected to be used in the actual project.

Road utilization adhesion coefficient real-time estimation for ASR system

The real-time estimation of road utilization adhesion coefficient is an important issue for the ASR (Anti-Slip Regulation) system of electric wheel independent drive vehicle. Firstly, the 1/4 vehicle dynamics model was built based on the LuGre tire model. Then combined with wheel angular velocity information, the exponential approach law-based sliding mode observer for the road utilization adhesion coefficient estimation was designed. And the observers asymptotic stability was proved also. Finally, at different conditions of constant target slip rate, variable target slip rate and ASR controllers of different type, the simulations of road utilization adhesion coefficient real-time estimation were done in the vehicle ASR process. The results show the effectiveness and robustness of the observer proposed.

A novel energy-coupling-based control method for double-pendulum overhead cranes with initial control force constraint

A novel energy-coupling-based control method for under-actuated double-pendulum overhead cranes with initial control force constraint is proposed in this article. The significant feature of the designed controller is its superior control performance as well as its strong robustness with respect to parameter variations and external disturbances. By incorporating a smooth hyperbolic tangent function into the control law, the proposed controller guarantees soft start of the trolley. Moreover, to improve the transient performance of the crane system, coupling behavior among the trolley movement, the hook swing, and the payload swing is enhanced by introducing a generalized payload horizontal-displacement signal. Lyapunov techniques and LaSalle’s invariance theorem are utilized to prove the stability of the designed closed-loop system. Simulation results demonstrate that the new energy-coupling control method achieves superior control performance and strong robustness over different payload masses, cable lengths, desired positions, and external disturbances with reduced initial control force.

Modeling and energy-based fuzzy controlling for underactuated overhead cranes with load transferring, lowering, and persistent external disturbances

In practice, vertical load motion is always involved in overhead cranes. In this case, the cable length turns from a constant to a variable, which may induce large amplitude load swing and make it more challenging to develop an appropriate controller. Most existing control methods for varying-cable-length cranes require either linearization or approximation to the original nonlinear dynamics; moreover, the case of external load disturbances is not fully considered. Inspired by these facts, we build the model and suggest an energy-based fuzzy control method for underactuated overhead cranes with load transferring, lowering, and persistent external disturbances. To estimate the persistent external disturbances, we construct a fuzzy disturbance observer. And a strict mathematical analysis of the control method without linearization approximation is presented, providing theoretical support for the superior performance of the proposed controller. Lyapunov techniques and LaSalle’s invariance theorem are used to demonstrate the stability of the closed-loop overhead crane system. Numerical simulation results are included to examine the effectiveness and robustness of the proposed method.

Mechanism Implementation for a 4WID/4WIS Unmanned Vehicle

This paper proposed a novel mechanism for an unmanned electric vehicle with four-wheel independent driving (4WID), independent steering (4WIS), independent suspending and independent braking. This unmanned electric vehicle adopted the technologies of driving by wire, steering by wire and braking by wire. Which improved the maneuverability of the vehicle greatly and made it achieving straight, oblique, lateral movement, zero radius turning and other movement patterns. Detailed implementation mechanism and virtual prototype of the vehicle were given in this paper. The hydraulic circuit schematic diagram and control method of the braking system were given also.