ERIT is one of the data-driven controls which tunes feed-forward controller parameters so that an estimated response is equal to a desired response. Although ERIT is practical in that the response is obtained before implementing the tuned parameters, few evaluation results that ERIT is applied to a real system have been reported. In this paper performance of ERIT was evaluated by applying ERIT to a proto-typed small heater. The controller was a two-degree-of-freedom control system consisting of feedforward control and feedback control, and it controlled internal temperature. Parameters of the feedforward control were tuned by ERIT. Errors between the internal temperature and the desired internal temperature calculated by a reference model were evaluated in reference models with different responsiveness. Both the minimum values of the errors and the maximum value of the errors after tuning were improved than those before tuning for all the reference models. The slower the response of the reference model, the larger the errors were. It is considered that a non-linearity according to the temperature deteriorates the followability to the reference model.
This paper describes optimal deployment and estimation method for arrival time for heterogeneous swarm of unmanned vehicles using semi-regular tessellation and simple formulation. Although recent researches have verified the effectiveness of swarm of unmanned vehicles at the time of natural disaster etc. and many researches related to them have been made, many of them target homogeneous swarm. On the other hand, it is more difficult to generalize and formulate the model of heterogeneous swarm because of their complexity. This paper proposes the method of generalizing heterogeneous swarm model and its optimal deployment in case of surveillance which is one of the most possible missions for them. Moreover, semi-regular tessellation in geometry has been applied which is one of the representative methods to fill the plane in general.
Japan's social capital stock was accumulated and concentrated during its era of high economic growth. However, in a future deterioration is a mounting concern. Over the next 20 years, facilities 50 years old or older will become increasingly common. Therefore, the urgent need exists to maintain and renew such aging infrastructure. Unfortunately many steel structures were constructed using frame-welded joints of fillet welded construction and a welded base. Moreover, these weld joints have little capacity to absorb energy during great earthquakes. Therefore, for designing steel structures incorporating welded joints, strong earthquake-resistance characteristics must be specially provided for those joints of steel welded bases. Furthermore, structural monitoring will be necessary. This report describes, using simple measurements and simulations, our piezoelectric joint sensors for evaluating resistance and displacement characteristics of fillet welded construction.
To suppress harmful parasitic vibrations in feedback control loop of a robot arm or flexible structures, a standard framework is based on sensor-actuator collocated configurations. In the case where the inertia on the load side is small, the sensor on the drive side may never detect vibration, and an effective design scheme is required to be developed which make use of remote sensors spatially separated from the actuator. It is well known that such a system is non-minimum phase and hard to design trade-offs between high nominal performance and robustness against some plant perturbations. This paper presents an approach to noncollocated vibration control using tip acceleration in a flexible slewing arm. The rigid body model of the arm is employed as a nominal model, and a tuning rule of the time delay in the phase compensator for vibration suppression is proposed focusing on the IMC (Internal model control) structure. The measured tip acceleration is provided with a phase compensator that consists of a time delay and bandpass filter for the vibration modes to be damped, and the dead time is designed so that the loop transfer function is around the positive real axis at the resonance frequency. This makes the Nyquist plot of the loop transfer function move away from the critical point, -1, to improve the disturbance suppression performance, and the performance deterioration is less likely to occur due to the uncertainty of the resonance frequency. Simulation and experimental study illustrate that effective vibration suppression is performed by using a tip accelerometer under disturbances and tip mass perturbations.