The Combination of Two Control Strategies for Series Hybrid Electric Vehicles

With most countries paying attention to the environment protection, hybrid electric vehicles have become a focus of automobile research and development due to the characteristics of energy saving and low emission. Power follower control strategy (PFCS) and DC-link voltage control strategy are two sorts of control strategies for series hybrid electric vehicles (HEVs). Combining those two control strategies is a new idea for control strategy of series hybrid electric vehicles. By tuning essential parameters which are the defined constants under DC-link voltage control and under PFCS, the points of minimum mass of equivalent fuel consumption (EFC) corresponding to a series of variables are marked for worldwide harmonized light vehicles test procedure (WLTP). The fuel economy of series HEVs with the combination control schemes performs better compared with individual control scheme. The results show the effects of the combination control schemes for series HEVs driving in an urban environment.      

悬挂输送机轴承自动注油脂润滑装置的研制

提出了间歇滚轮啮合跟踪捕捉方法．并以此方法设计了自动注油润滑装置．它通用于等节距滚子悬挂输送机和不等节距滚子悬挂输送机的自动跟踪注油脂润滑．该装置完全是自动机械机构学原理设计,不需要电控系统和自身动力,工作可靠的随动自动机械装置．     

Flipped voltage follower based fourth order filter and its application to portable ECG acquisition system

This paper presents the designing of a compact flipped voltage follower (FVF) based fourth order low-pass filter (LPF). The circuit is designed by cascading current-reuse P-FVF and N-FVF biquads operating in sub-threshold region. The circuit attains a cut-off frequency of 206.14 Hz designed for portable ECG acquisition system. The proposed circuit is simulated in 0.13  μm CMOS technology in Cadence environment. The circuit occupies a chip area of 180.310  μm × 552.390  μm i.e. 0.0996 mm². LPF consumes 2.46 nW power with a supply voltage of 0.5 V. It provides a dynamic range of 65.17 dB with input referred noise of 22.214μVrms, HD₃ of 60.3 dB with 50 mVpp 50 Hz frequency. The circuit is compared with state of the art LPFs which provides the best figure of merit and shows enhanced performance in terms of noise, HD3 and dynamic range with lowest supply voltage and technology node.     

Finite-time consensus for multi-agent systems with globally bounded convergence time under directed communication graphs

In this paper, we study the finite-time consensus problems with globally bounded convergence time also known as fixed-time consensus problems for multi-agent systems subject to directed communication graphs. Two new distributed control strategies are proposed such that leaderless and leader-follower consensus are achieved with convergence time independent on the initial conditions of the agents. Fixed-time formation generation and formation tracking problems are also solved as the generalizations. Simulation examples are provided to demonstrate the performance of the new controllers.     

Adaptive formation control of autonomous underwater vehicles with model uncertainties

This paper investigates the formation control problem of underactuated autonomous underwater vehicles (AUVs). What makes this problem different and challenging is that, in the AUV model, the mass and damping matrices are not diagonal with nonzero off‐diagonal terms and unknown hydrodynamic damping terms. To address the effect of nonzero off‐diagonal terms, we introduce a coordinate transformation, while the unknown hydrodynamic damping terms are approximated adaptively by a neural network. Then, a leader‐follower control strategy is presented, where each follower needs to track a virtual vehicle. This strategy translates the formation control problem into a set of position (including heading) tracking problems for the following AUVs. The position and heading tracking controller is designed based on Lyapunov direct method and backstepping technique, taking into account the effect of the nonzero off‐diagonal terms in the mass matrix and the unknown hydrodynamic damping terms. Simulations are given to demonstrate the effectiveness of the control method proposed.     

基于包络原理的圆锥滚子摆杆从动件圆柱凸轮的解析设计

利用空间啮合原理及旋转变换矩阵法 ,给出圆锥滚子摆杆从动件圆柱凸轮的廓面方程及压力角的精确解 ,为该机构的CAD/CAM的建立及凸轮廓面加工方法的改进奠定了理论基础。     

某型火炮立靶密集度的探讨

阐述影响某型火炮立靶密集度因素,提出提高立靶密集度的措施。     

一种缓冲器阻抗动态调整的LDO

提出了一种缓冲器阻抗动态调整的LDO结构。采用并联负反馈和阻抗动态调整技术,显著降低了缓冲级的输出阻抗,没有增加额外的静态电流,功率管栅极极点始终远在单位增益带宽之外,对稳定性没有影响。该缓冲级增大了功率管栅极的摆率,提高了LDO瞬态响应性能。基于TSMC 0.18 μm 3.3 V CMOS工艺进行设计,该LDO的输出电压为1.8 V,压差电压为0.2 V,最大输出电流为100 mA。仿真结果显示,LDO的静态电流只有5 μA,当负载电流在10 ns内从0 mA跳变到100 mA时,输出欠冲和过冲电压分别为88.2 mV和34.8 mV。     

搅拌生物反应器的循环时间分布和混合结构模型

利用磁粒子流动跟踪法对搅拌生物反应器的循环时间分布进行测定,并将Rushton径向流桨和两种新型轴向流桨在不同介质粘度和转速下的循环时间分布进行比较和性能评价。建立了单桨搅拌生物反应器的混合结构模型,对循环时间分布数据进行拟合,求得模型参数,进而讨论了不同实验条件下模型参数的变化。结果表明,对于非牛顿、高粘度发酵过程,轴向流桨比Rushton桨具有更好的混合特性。     

样条函数在凸轮机构设计中的应用

从实现机器工作过程的特殊位置点要求出发,采用三次插值样条函数来确定凸轮机构从动件的运动规律,进行凸轮轮廓曲线的设计。