Adaptive fuzzy sliding mode control for coordinated longitudinal and lateral motions of multiple autonomous vehicles in a platoon

In this paper, the platoon control problem of autonomous vehicles in highway is studied. Since the autonomous vehicles have the characteristics of nonlinearities, external disturbances and strong coupling, a novel adaptive fuzzy sliding coordinated control system is constructed to supervise the longitudinal and lateral motions of autonomous vehicles, in which the fuzzy system is employed to approximate the unknown nonlinear functions. Due to the low sensitivity to disturbances and plant parameter variations, the proposed control approach is an efficient way to handle with the complex dynamic plants operating under un-certainty conditions. The asymptotic stability of adaptive coordinated platoon close-loop control system is verified based on the Lyapunov stability theory. The results indicate that the presented adaptive coordinated platoon control approach can accurately achieve the tracking performance and ensures the stability and riding comfort of autonomous vehicles in a platoon. Finally, simulation test is exploited to demonstrate the effectiveness of the proposed control approach.     

陶瓷砂应用于芯砂的问题与对策

本文对陶瓷砂用于芯砂时出现的问题进行了分析并提出相应的解决措施.     

A vehicle cloud control system considering communication quantization and stochastic delay

A novel kind of networked feedback controller is designed for the vehicle cloud control system in the presence of both sensor-controller/controller-actuator delay and communication quantization. Firstly, the vehicle cloud control system with delayed and quantized communication is modeled using the lateral/longitudinal vehicle dynamic and Markovian jump linear system (MJLS) theory. Then, some efficient stabilization conditions in matrix inequalities forms are derived for the considered cloud-controlled vehicles. Furthermore, a cone complementary linearization method is utilized to solve the nonlinear matrix inequalities involved in the stabilization conditions. Simulation tests on connected vehicle lateral and longitudinal control are conducted to verify the effectiveness of the analytical results. Compared with the commonly used constant-parameter controllers, the proposed method is practical to design vehicle cloud controllers under stochastic delay and communication quantization scenarios, with known delay distribution. Lastly, the stability of the vehicle cloud control system is guaranteed under the infection of unreliable communication factors with the proposed control method.     

防止WP12气缸体夹砂缺陷的对策

本文分析了WP12气缸体毛坯在大批量生产过程中，产生起皮夹砂缺陷的原因，总结了在生产实践中解决其缺陷所采取的工艺措施和取得的效果。     

Disturbance decoupling robust control of vehicle full speed cruise dynamic system

In this study, an innovative dynamics model of LFS (longitudinal vehicle full-speed cruise system) is developed by lumping the dynamics of a controlled vehicle and an inter-vehicles together. On account of the external disturbance, parameters uncertainty and the nonlinearity within LFS, a DDRC (disturbance decoupling robust control) method is proposed. For this method, the theory of NDD (nonlinear disturbance decoupling) is utilized firstly to separate the external disturbance from certain part of the proposed dynamics model. Then, the invariance over the sliding mode of VSC (variable structure control) is used to eliminate the influence of remaining uncertain part. Finally, the DDRC method is adopted to design an LFS ACC (adaptive cruise control) system, and some numerical simulations are carried out to validate its performance. The simulation results demonstrate that the proposed control system not only exhibits an expected dynamic response, high tracking accuracy and a strong robustness, but also achieves a global optimization by means of a simplified control structure.     

An adaptive cascade trajectory tracking control for over-actuated autonomous electric vehicles with input saturation

This paper presented a novel adaptive cascade nonlinear trajectory tracking control scheme of over-actuated autonomous electric vehicles involving input saturation. First, a nonlinear vehicle dynamic model with input saturation is established, which can accurately describe the features of uncertainties and coupling of autonomous electric vehicles, and the hyperbolic tangent function is designed to estimate the saturation function for dealing with the input saturation problem. Then, a novel adaptive cascade trajectory tracking control scheme is designed. An adaptive neural network-based terminal sliding control law is proposed for producing the generalized force/moment in real-time, the asymptotic stability of this adaptive control system is proven by Lyapunov theory, and a quasi-newton distribution law is designed to determine the optimum tire forces that guarantee the actual generalized forces/moment are close to the desired values. Finally, simulation results demonstrate the effectiveness of the proposed control scheme.