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This paper describes the utilization of the product model by SysML as a joint platform for distributed design. We introduce a typical design process involving distributed design teams. In particular, this process allows a thermal design of cavities, i.e., air space inside the enclosure, in terms of flow rate, acoustic radiation resistance and so on. Then, we investigate a module-based design optimization approach defining cavity as a module to efficiently support such processes. Authors propose structural and functional modeling that enables all the distributed design sites to share the design information with the product model. Using this design framework, it will be possible to prevent performance defects due to physical coupling between modules, and thus, reduce the iteration of work.

This paper presents control system design for occupant lower extremities protection in vehicle frontal collision. A protective control system consisting of an active knee bolster and an active lap belt is designed to reduce the maximum load to the femurs and the maximum lap belt force. In the control system design, we examine the effects of the initial distance between the occupant's knees and the active knee bolster, and the maximum pelvis displacement. It is expected that the initial distance affects the protection performance because the control duration of the active knee bolster mainly depends on the initial distance. To avoid the collision with the steering wheel, the maximum pelvis displacement is restrained. The lap belt force and the contact force between the knees and the instrument panel are calculated so that the load to the femurs is reduced while the lap belt force is not increased compared to passive lap belt. Simulation results clarify the effects of the initial distance and the maximum pelvis displacement on occupant protection under assumption that the protective control system can vary the initial distance.

In this paper, to realize the comfortable steering feeling during driver's steering or a rough road running, we design a control system of an electric power steering (EPS) for a vehicle with an active stabilizer. Although control systems of the conventional EPS are designed generally to obtain the comfortable steering feeling similar to that using a hydraulic power steering (HPS), the steering feeling might not be realized on a rough road. We propose a design strategy for the control system of the EPS in consideration of the active stabilizer to avoid side effects to the steering system by the reaction force of the front tire due to roll stiffness control for the active stabilizer. According to the design strategy, a controller of the EPS is designed and tuned to realize the HPS-like steering feeling by applying a gain-scheduled control corresponding to both a vehicle speed and a sensor torque on a steering axis in consideration of the active stabilizer, which is designed so as to not only reduce the roll motion of a vehicle body but also suppress the restoring torque which acts on the steering axis through the front tire during the rough road running. It is verified that the control system of the EPS designed is effective to realize the HPS-like steering feeling during the driver's steering and suppress the rotational vibration of a steering wheel during the rough road running.

In this paper, a dynamical model of a motorcycle, which consists of four rigid bodies with nine degrees of freedom, is presented. In this model, the cross-sectional shape of the tire is described as a half-circle and its deformation is taken into account. By taking account of the tire slip condition or the tire nonslip condition in the longitudinal direction of the wheels, each equation of motion is derived. Also, by carrying out simulations, it is verified that the responses to the front steering impulsive torque are in good agreement with the results obtained using commercial software. Moreover, the longitudinal friction force and the lateral force in a turning maneuver are analyzed.

When large external forces come from road, a suspension stroke reaches the limitation and the riding comfort may reduce. In order to overcome this problem we propose a new control method for an active suspension which can avoid reaching the stroke limitation. A sliding mode controller is designed in consideration of rigidity variation of the spring. Also in order to estimate the internal state of the suspension, VSS (Variable Structural System) observer is designed without information of nonlinear force which occurred in rigidity variation when the suspension reaches the stroke limitation. By carrying out simulation and experiment of a quarter-car suspension model it is verified that the performance of the controller is superior to that of the method, which switches to a passive damper near the stroke limitation from LQR (Linear Quadratic Regulator) in the range of small stroke.

This paper deals with damage detection and vibration control of a smart structure. A finite element model of a cracked beam is established. This model is applied to a cantilever beam and the natural frequencies are determined for a different crack length and locations. This study proposes a method for the crack identification when the vibration of the beam is suppressed by using active control. Once cracks are present in structures, the control performance becomes worse. This is because both eigenvalue and eigenvector of the beam vary. So, in this study we design the gain-scheduled controller considering both the crack length and the location. To obtain the linear parameter-varying (LPV) model for controller design, its Frobenius norm is measured. The efficiencies of our crack identification method and the gain scheduled controller design are verified by simulation.

Time delay by image processing exists in the information acquired from a CCD camera. Since renewal time of image information is longer than sampling time of control, control delay occurs and lowers the performance of feedback control. In this paper, in order to compensate image information delay, we propose the method that combined Kalman filter, time delay compensation, and state estimation between the sample points of image information. Advantages of the proposed method are demonstrated by simulation and experiments for the three-link space robot.

In this paper we propose a design method for active seismic isolation control taking account of actuator saturation. By using a hyperbolic tangential function that is differentiable to controller output, we formulate the linear parameter varying system according to the controller output and design a gain-scheduled controller. By carrying out simulations and experiments of seismic excitation, our proposed gain-scheduled controller is compared with an H∞ fixed controller or a sliding mode controller. It is verified that the proposed controller maintains performance of isolation even if a large earthquake with which the actuator saturation occurs comes, although the other controllers lower the performance than uncontrolled case.

In this paper we try to realize the active control of shock by an experimental procedure, in which the collision between two objects is controlled so as to make the deformation of one object large and the other small. Two control systems are applied to this experiment. One of them is an LQI control system with Kalman filter and the other is an H∞ control system. In both systems, we proposed a controller switching at a time when the object deforms from the elastic range to the plastic range. In order to evaluate effectiveness of control, the deformation ratio between the objects is introduced. In our experiment the discretized control system is implemented in a digital signal processor used to realize real-time control. As a result of experiment it was verified that the active control of shock is realizable and the controller we designed is useful for shock control.

In this paper, we deal with a three-link space robot moving in planar space without controls for the base attitude. Our experimental setup of the three-link space robot can levitate by use of compressed air. Using d'Alembert principle, it is shown that the state equation of the three-link space robot can be reconstructed as a first-order nonholonomic system with the constraint condition that the rotational velocity of the base is set to be zero. The suitable final postures corresponding to the desired position of the end effector can be determined using the concept of the enhanced disturbance map. Based on the state equation, the feedforward torque inputs can be obtained by the final-state control in order to bring the end effector from an initial position to the desired position. The torque inputs and trajectories obtained are smooth. We designed a two-degree-of-freedom control to follow the obtained trajectory. It is verified from simulation and experiment that the proposed method of motion control is useful.

In this paper, we propose a method of control system design which takes the actuator saturation into consideration. By using a hyperbolic tangential function as the saturation function, we introduce both the time derivative of the controller output and the anti-windup control structure with the feedback loop of the error between the controller output and the saturation function output. Furthermore, we formulate a linear parameter-varying system to design the gain-scheduled controller. The effectiveness of our proposed method is verified by carrying out the experiments of the positioning control for a cart and inverted pendulum system.

System identification of a motorcycle by Computer-Aided Dynamics Analysis is introduced to design a control system for the attitude stabilization. The identified model can be reduced to the coupled mode system between the roll mode and the front-steering mode. We design the gainscheduled front-steering control system using the roll angle as the feedback signal, which is according to the varying parameter of motorcycle velocity. It is verified from simulation results that the motorcycle attitude against disturbances is stabilized by the gain-scheduled controller at the wide range velocity.