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Industry 4.0 accelerates the growth of unmanned technology that reduces the labor cost and creates high automation in manufacturing system. The automated guided vehicle which is capable of transferring materials or executing tasks without human intervention becomes a necessary system for modern unmanned factories. The study explores the guidance and control design to accomplish the common task of path-following control for unmanned ground vehicles (UGV). A complete design method is presented that includes the lateral-directional autopilot, the vector field guidance for path-following, and multi-sensor fusion. The lateral-directional autopilot produces the low-level control action, the higher level guidance indicates the course direction of UGV at every spatial point based on the lateral path error, and the accurate UGV position relies on the estimate obtained by dynamically fusing sensors with extended Kalman filter. The design parameters in every stage are analyzed theoretically first and then fine-tuned in practice. The process is clearly described in this study, and the field test results are discussed in details to verify the performance of the proposed method and demonstrate the superiority over others.

The design of an intelligent exoskeleton robot with pneumatic artificial muscles for human lower limb motion assist using electromyography (EMG) is presented. There are four topics addressed in this paper. Decoding electromyography is the first topic. When muscles are active, they produce an electrical activity. EMG is a record of this electrical activity that reflects human’s movement. Through regression analysis a model is obtained to extract motion commands from EMG. It would be an advantage to employ EMG as a control signal for the exoskeleton control. Second, the pneumatic artificial muscle, air muscle for short, is a simple and powerful actuator. When actuated with compressed air, it contracts and provides a pulling force. As a result of its behavior in a similar way to a biological muscle, air muscle is adapted for a bionic actuator of the assist robot. The force models of air muscles are investigated by experiments in a workbench. Third, for the control of a bionic-inspired robot, the multimodal sensory feedback including EMG and inertial sensors is necessary. By using EMG as a force-proportional measurement between human and robot, a control system combined a sensor-fusion approach and a compliant mechanism enables exoskeleton to carry out human-robot collaboration. Finally, a prototype of power-assist exoskeleton robot for lower limb is completed and evaluated by experiments successfully.

Due to the unique electric-mechanical coupling effects, piezoelectric materials are widely used in sensors and actuators. Not only in smart structures but also in structural health monitoring, the developments of piezoelectric materials combined with the micro electro mechanical system (MEMS) techniques make our lives totally different. This paper provides a series of numerical simulations about the circular piezoelectric plate with a hole in the plate by using the special boundary element method (BEM). The Green’s functions of BEM are obtained from the derivation of extended Stroh formalism. By this formalism, the analytical closedform solutions of hole in an infinite piezoelectric medium under various loading conditions are obtained. The results demonstrate the coupling effects with different boundary conditions in the circular plate, which will satisfy the requirements of the designers who need to use the products with the hole in the piezoelectric circular plate.

The study designs an autopilot of an unmanned ground vehicle (UGV) to perform navigation and control. The graphical programming language LabVIEW is used to make the task of control systems engineering clear and easy to handle. The speed and direction of the three-wheel UGV are controlled by two DC motors. The essential lateral direction control with the inner loop for steering angle control and the outer loop for heading angle control is designed by successive-loop-closure approach. The controller gains are tuned by on-line closed-loop system test. The lateral guidance strategy for achieving straight-line path following is to construct a vector field of desired heading relative to the desired path that results in the UGV moving toward the path. The experimental results from HIL simulations and field test show that the proposed autopilot is effective for navigation and control of an UGV.

Due to the reality of the equipment assembly under the high speed train, an intelligent omni-directional mobile platform is developed. The principle and structure of the platform are discussed .The intelligent omni-directional mobile platform is designed and applied. It has proved in practice that the intelligent omni-directional mobile platform based on above designs can move fluently and accurate in the limited assembly space. Assembly efficiency and quality of the equipment under the high speed train can be improved effectively.

The technology of hardware-in-the-loop simulations (HILS) plays an important role in the design of complex systems, for example, the structural health monitoring (SHM) of aircrafts. Due to the high performance of personal computers, HILS can provide practical solutions to many problems in engineering and sciences, especially in the huge systems, giant dams for civil engineering, and aircraft system. This study addresses the HILS in hole/crack identification in composite laminates. The multiple loading modes method is used for hole/crack identification. The signals of strains measured from the data-acquisition (DAQ) devices are accomplished by the graphical software LabVIEW. The results represent the actual responses of multiple loading mode tests of real specimens. A personal computer is employed to execute the identification work according to the strain data from DAQ devices by using a nonlinear optimization approach. When all the criteria are satisfied, the final identification results will be obtained. HILS will achieve real time identification of hole/crack in the composite plate by using the actual response measured from the sensors. Not only the size, but also the location and orientation of the crack/hole in a composite plate are successfully identified herein.

The piezoelectric material generates an electric field when it is deformed by an external force. On account of this electro-mechanical coupling, piezoelectric material plays an important role in the development of sensors as well as actuators. The governing equations of electro-mechanical characteristics are expressed by extended Stroh formalism. The boundary element method is applied to solve the finite domain problem in which the Green function derived according to boundary conditions is embedded. The essential nonlinear identification problem is solved by using the multiple loading modes and stepwise optimization to search for the global minimum solution. This paper successfully identifies the hole/crack size, location, and orientation in finite circular piezoelectric plates by using the strain/electric field data, stress/electric displacement data, or displacement/electric charge data from static loadings. The numerical results that confirm the effectiveness of the proposed method for hole/crack identification in circular piezoelectric plates are presented in details.

In this paper, a new design of adaptive iterative learning control (ILC) for a class of uncertain nonlinear systems is proposed for the purpose of state tracking and improving convergence speed with both parametric and nonparametric uncertainties. The main feature of the design is that the controller signal is continuous due to the use of integral and employment of second-order sliding mode technique. Nonparametric uncertainties such as norm-bounded nonlinear uncertainties satisfying local Lipschitz condition can be effectively handled. In response to unknown bounded disturbances, a continuous sliding mode adaptive iterative learning control is more robust. By designing a suitable controller and composite energy function, the convergence of tracking error sequence within a small neighborhood of the origin is achieved in the iteration domain. In the end, an illustrative example is presented to demonstrate the efficacy of the proposed ILC scheme.

Many kinds of gold wire and bond profiles have been used in wire bonding technology. To date, no solid experimental results have been available to guide the bond designer in the choice of a better looping system. A method is proposed for evaluating the sweep resistance of wire bonds during the transfer molding process. The wire sweep method was developed to obtain load-transverse displacement curves of wire bonds. The sweep stiffness of a wire bond is defined as the index of sweep resistance to drag during the transfer molding process, and can be evaluated on the basis of the load-transverse displacement curves. A wire bond with high sweep stiffness possesses a low wire sweep and sag for integrated circuit packaging. In this study, three types of wire bonds, Q-loop, S-loop and M-loop bonds, were examined to determine the sweep stiffness. The results showed that the Q-loop bond has the highest sweep stiffness for fixed bond spans and bond heights. For longer connections or crossing another chip in multi-chip module/three-dimensional packages, the M-loop bonds were affected significantly by their kinking numbers within a bond. The experimental results indicated that the M-loop bond has 13-75% better sweep resistance than the S-loop bond, depending on the bond span and bond height used.

The purpose of this research is to estimate the dimensional stability derivatives in linear dynamic model of a fixed-wing model-scale unmanned aerial vehicle (UAV) by real flight data logged by an onboard flight computer. The paper described the experimental setup, operation procedure of raw flight data, process of nonlinear least squares estimation, and cause-effect examination of impulse responses. The simulation-based results of the estimated model indicated a very good accuracy with real flight data. The linear longitudinal and lateral models are very helpful for designing the stability-augmentation system or autopilot for the UAV.

Owing to a great decrease in size and weight, the pointing accuracy of microsatellite is vulnerable to space environmental disturbances and the internal uncertainty of moment-of-inertia variation. Mixed H 2 / H ∞ control, giving consideration to both stability robustness and root-mean-square (rms) performance, is particularly attractive for attitude controller design of microsatellites. By using linear matrix inequality method, the numerical solution of mixed H 2 / H ∞ state-feedback controller can be efficiently solved. The performance differences between mixed H 2 / H ∞ controller and its two extremes—pure H 2 controller and pure H ∞ controller—are discussed in detail. Mixed H 2 / H ∞ controller shows the remarkable capability of achieving a balanced compromise between H 2 and H ∞ performances.

A cruise controller for two typical traction types of high speed train (HST), the push-pull driving (PPD) type and the distributed driving (DD) type, are designed using a mixed H2

A low-cost and high-fidelity flight simulation training device (FSTD) has been developed for the purpose of research and education. With inexpensive and easy obtained materials, the FSTD duplicates a realistic cockpit and relevant hardware of the airplane Beech 1900C. The computational platform is a PC-based cluster system. The commercial-off-the-shelf (COTS) software of Microsoft Flight Simulator 2004 is the computational kernel of the simulation system. Two middleware, named as FSUIPC and WideFS, are used for data interchange between cluster computers. An instructor workstation is included in this system to manage the mission of the flight simulation. USB 2.0 interface is also adopted for connecting the cockpit hardware and the hardware control computer (HCC).

This chapter describes a continuing research on design and verification of the autopilot system for an unmanned aerial vehicle (UAV) through hardware-in-the-loop (HIL) simulation. UAVs have the characteristics of small volume, light weight, low cost in manufacture, high agility and high maneuverability without the restriction of human body physical loading. Equipped with the on-board autopilot system an UAV is capable of performing out-of-sight missions that inspires scientists and engineers with a lot of innovative applications. Not only in the military but also in the civil, the applications of UAVs are in full bloom. Apparently one of the key challenge of UAV research and development is its autopilot system design. For the purpose of designing an autopilot, the technology of hardware-in-the-loop simulation plays an important role. The concept of HIL simulation is that a stand-alone personal computer is used to simulate the behavior of the plant, several data-acquisition devices are exploited to generate the real signals, and the prototype controller can be tested in real-time and in the presence of real hardware. HIL simulation presents a new challenge of control engineering developers as the “correctness” of a real-time model not only depends upon the numerical computation, but the timelines with which the simulation model interacts with external control equipment that is the major difference between HIL simulation and numerical simulation. Due to the useful feature, HIL simulation is applicable to solve many problems in engineering and sciences effectively (Shetty & Kolk, 1997; Ledin, 2001). HIL simulation provides an effective technique for design and test of autopilot systems. Using HIL simulation the hardware and software at subsystem level perform the actual input/output signals and run at real time so that the test target (e.g. prototype controller) is working as if in real process. This provides the ability to thoroughly test subsystems under different working loads and conditions; therefore, engineers can correct and improve their original designs early in the development process. The advantages of HIL simulation are reducing the risk in test and shortening the development time. Especially HIL simulation is suitable for critical or hazardous applications. (Cosic et al., 1999) used TMS320C40 DSP to set up a HIL simulation platform for a semiautomatic guided missile system. (Carrijo et al., 2002) applied HIL simulation to test the onboard computer on a satellite launcher vehicle for motion and attitude control. (Sun et al., 2006; Sun et al., 2008a; Sun et al., 2009; Sun et al., 2010) developed the HIL simulation system to evaluate the performance of UAV autopilot that was employed different control laws.

To study the effect of behavioral training on the learning and memory abilities and changes of NR2B and GluR1 expressions in the hippocampus of offspring rats with fetal growth retardation (FGR).A FGR model was established in SD rats by passive smoking. The offspring rats were divided into FGR group and control group, each then randomized into training and untrained group. Morris water maze behavioral training was carried out in postnatal months 2 and 4, and the learning and memory abilities of the young rats were assessed using dark-avoidance test and step-down test. NR2B and GluR1 expression in the hippocampus of the rats were detected by immunohistochemistry.In the dark-avoidance and step-down tests, the FGR rats showed deteriorated learning and memory performance in comparison with the control group, but behavioral training resulted in improved performance of the rats. The performance in FGR group was much improved after behavioral training, and the model factor and the training factor showed a significant interaction (P0.05). The expression of NR2B and GluR1 in CA1 and CA3 regions of the hippocampus decreased in FGR group, then the their expressions in the CA1 region increased after training in both FGR and control groups, and the increment was especially obvious in GluR1 expression in the CA1 region at postnatal month 2. The two factors showed a significant interaction (P0.05).Behavioral training can improve the learning and memory abilities of FGR offspring rats, the mechanism of which is probably related to increased expression of NR2B and GluR1 in the CA1 region of the hippocampus.

Since the unmanned aerial vehicles (UAVs) bring forth many innovative applications in scientific, civilian, and military fields, the development of UAVs is rapidly growing every year. The on-board autopilot that reliably performs attitude and guidance control is a vital part for out-of-sight flights. However, the control law in autopilot is designed according to a simplified plant model in which the dynamics of real hardware are usually not taken into consideration. It is a necessity to develop a test-bed including real servos to make real-time control experiments for prototype autopilots, so called hardware-in-the-loop (HIL) simulation. In this paper on the basis of the graphical application software LabVIEW, the real-time HIL simulation system is realized efficiently by the virtual instrumentation approach. The proportional-integral-derivative (PID) controller in autopilot for the pitch angle control loop is experimentally determined by the classical Ziegler-Nichols tuning rule and exhibits good transient and steady-state response in real-time HIL simulation. From the results the differences between numerical simulation and real-time HIL simulation are also clearly presented. The effectiveness of HIL simulation for UAV autopilot design is definitely confirmed

To test the impact of fetal growth restriction (FGR) on the spatial learning and memory abilities of the offspring of rats.FGR Model of Sprague-Dawley rats was constructed according to the method of passive smoking. The offspring of the rats were divided into male FGR group, male control group, female FGR group and female control group. Within each group, the rats were randomly divided into three subgroups to be tested at 1, 2, and 4 months of age, respectively (n =10 for each subgroup). Morris water maze task was performed to assess the spatial learning and memory abilities of the rats.The escape latencies to find the platform were shortened with increased training times for all of the rats. At the age of 1 and 2 months, both male and female rats in the FGR group spent more time in finding the platform than their counterparts in the control group (P0.05). At the age of 4 months, significant prolonged latency was only found in the female rats. The rats in the FGR group, except the 4 months old male rats, were more likely to use non-effective strategies (random or marginal strategies) to find the platform than the efficient strategies (tendency or straight strategies). The rats in the FGR group stayed in the platform shorter than those in the control groups (P0.05).FGR can cause gender- and age-specific impairment of spatial learning and memory abilities to the offspring.

The materials used in this study were three types of gold wire: SR-Y, high-loop wire; FA type, middle-loop wire; and GL-2, low-loop wire. All of these wires are composed of high-purity gold with various dopants added to obtain greater strength and stiffness. The three types of gold wire are gold alloys of 99.99% purity with less than 100 ppm of non-gold dopants. The major difference among these three types of wires is the concentration of calcium dopant: SR-Y, 1 ppm; FA, 6 ppm; and GL-2, 24 ppm. The effects of a calcium dopant on the thermomechanical properties of three types of gold-bonding wires were investigated. The sweep stiffness were measured for various bond spans and bond heights of three types of wire and was shown to increase with increased concentration of calcium.

A new and straightforward approach to mixed psynthesis is proposed. The main idea is that the structure singular value can be equivalent to an weighted H2 system norm by shaping a frequency-dependent weight. The resulting controller obtained from a sequence of weighted H2 optimizations may possess robust performance property from p criterion. Two successful designs are given to stress the superior ability of the H2-based loop-shaping method for mixed p-synthesis.

Synthesis of optimal H/sub /spl infin// controllers is formulated as a loop-shaping problem where the desired closed-loop shape to be pursued is a flat frequency response of the largest singular value. The weighted H/sub 2/ optimization technique used in LQG/LTR is exploited in the loop shaping procedures to generate a sequence of H/sub 2/ controllers converging to the optimal H/sub /spl infin// controller. The resulting optimal H/sub /spl infin// controller not only has the inherent robust property due to H/sub /spl infin// criterion but also possesses the nice H/sub 2/ control structure, being easy to compute and implement. A flight control example is demonstrated to show that the numerical accuracy of the present LQG-based H/sub /spl infin// synthesis is comparable to the conventional H/sub /spl infin// approach, i.e. /spl gamma/-iteration.

A new and straightforward approach to mixed /spl mu/-synthesis is proposed. The main idea is that the structure singular value can be equivalent to a weighted H/sub 2/ system norm by shaping a frequency-dependent weigh t. The resulting controller obtained from a sequence of weighted H/sub 2/ optimizations may possess a robust performance property from a /spl mu/ criterion. Two successful designs are given to stress the superior ability of the H/sub 2/-based loop-shaping method for mixed /spl mu/-synthesis.

A satellite has an astronomical survey mission requiring accurate pointing of a scientific sensor package. This package must be maintained in the quietest possible environment, which entails isolating it from the vibrations and electrical noise of the main service body. The pointing requirement arises when it is necessary to point the unit in another direction, it can be met by dynamics with a transient settling time of 20 seconds and an overshoot of no more then 15%. We model the satellite as two masses connected by a spring with torque constant k and a viscous-damper with damping constant b . Physical analysis leads us to assume that the parameters k and b vary as a result of large temperature fluctuation. The attitude pointing requirement must be satisfied for any parameter values in a prespecified range. We will synthesize the robust controller to achieve the specified performance requirement in the presence of parameter uncertainties.

Addresses the dynamics and optimal cruise control of concentrated-driven high speed train. The dynamical model is completed by a multi-body system, in which couplers connecting adjacent vehicles are characterized by nonlinear hardening/softening springs. The design specification is a mix of command tracking and disturbance rejection. The authors apply a linear matrix inequalities approach to synthesize a multi-model multi-objective (H/sub 2//H/sub /spl infin// performance) state-feedback controller. Numerical simulations show the validity of the resulting controller.