Meifen Cao

A design method of neural oscillatory networks for generation of humanoid biped walking patterns

We analyse the mechanisms of human walking patterns and propose two design methods of neural oscillatory networks for generating various desired biped walking patterns of an 8 joints model in 3D plane. First, we discuss how the construction and the parameters of the network determine the inner state variable of each neuron in the network. Then we try to use two different methods to build the suitable network which can generate the desired walking patterns. The first method is to lower the system dimension to 3/spl times/n by considering some mechanisms in human walking and solve the connection weights of the network by the harmonic balance method. The second method is to calculate all kinds of connections of the network by genetic algorithms. From the results of simulations the methods were proved to be effective.

Measurement of the tractive force and the new adhesion control by the newly developed tractive force measurement equipment

The acceleration and deceleration rate of the train depend on the tractive force. When the wheels of the train slip on the rails, the torque is decreased to avoid the continuous slipping. The reason is that the tractive coefficient between the wheels and the rails has a peak at a certain slip velocity. But this adhesive phenomenon is not clearly examined or analyzed. Thus we have developed a new adhesion test equipment. In this paper, we measured the tractive force with this equipment, and clarified the adhesive phenomenon. Then we proposed a new tractive force control and verified the effectiveness of the proposed control scheme.

Maximum adhesion control for Shinkansen using the tractive force tester

The acceleration and deceleration rate of the train depend on the tractive force. When the wheels of the train slip on the rails, the electric torque is decreased to avoid the continuous slipping. This reason is that the tractive coefficient between the wheels and the rails has a peak at a certain slip velocity and the over slipping should be avoided. But this adhesive phenomenon is not clearly examined or analyzed. Thus we have developed new adhesion test equipment, and we measured the tractive force with this equipment, and clarified the adhesive phenomenon. Then, we proposed a maximum tractive force control in the slip region and verified the validity of the proposed control scheme.

Experimental verification of disturbance-observer-based active filter for resonance suppression

In the case of harmonic compensation based on the detection of the line current, a problem of the resonance between the active filter (AF) and an LC filter often arises if an LC filter is connected parallel to the AF Thus, the disturbance observer is introduced to solve this problem. By the estimation of the harmonics disturbance using the proposed disturbance observer, the compensation characteristics of the AF are improved and the resonant current can be compensated. In this paper, the theoretical analyses of resonance, a design of the disturbance-observer-based AF, and the experimental results are presented.

Adhesion control in low-speed region and experiment verification with considering low-resolution pulse generator

An adhesion control performance in low-speed region considering a low-resolution pulse generator (PG) and experiment results are reported. In the proposed adhesion control methods, the wheel speed is required. However, in the railway field, the PG used for the wheel speed measurement is attached on the main motor and with only 60 pulse-per-revolution (ppr). Therefore, in the low-speed region, the speed value cannot be obtained in each control period. To solve this problem, a disturbance-instantaneous speed observer is proposed in this paper. The effectiveness of the proposed adhesion control with instantaneous wheel speed estimation has been verified by simulations and experiments.

An evolutionary design scheme of neural oscillatory network for generation of biped walking patterns

This paper presents a new scheme for the design of a neural oscillatory network which can be used to generate the desired biped walking pattern trajectories. The scheme is based on evolutionary computation concepts and can solve all of the connection weights in the network according to the desired walking pattern parameters. It also has the advantages in the simplicity, flexibility and high calculation speed. With the results of simulations the scheme proved to be effective. This research also established a foundation for the research on expressing various human walking patterns in mathematical models.

Measurement of tractive force during acceleration and deceleration periods

The acceleration and deceleration ability of the train depend on the tractive force. When the wheels of the train slip on the rails, the electric torque is decreased to avoid the continuous slipping. This reason is that the tractive coefficient between the wheels and the rails has a peak at a certain slip speed. But this adhesive phenomenon is not clearly examined or analyzed. Thus we have developed a new tractive test equipment. We measured the tractive force with this equipment, and clarified the adhesive phenomenon. In this paper, the measurement results of the tractive coefficient (during the acceleration and the deceleration periods) and a discussion on the experimental results of the maximum tractive force control are reported.

A design scheme of neural oscillatory networks by hierarchical evolutionary calculation for generation of humanoid biped walking patterns

Humanoid biped walking patterns attracts more and more attention both in the fields of robotics and prosthetics. This paper presents a new scheme for the design of a neural oscillatory network which can be used to generate the desired walking pattern trajectories. The scheme is based on the evolutionary computation concept, and has the advantages of simplicity, flexibility, and high calculation speed. The scheme proved to be effective from the results of simulations. This research also established the foundation for research on expressing various human walking patterns in mathematical models.

Measurement of Tractive Force and the New Maximum Tractive Force Control by the Newly Developed Tractive Force Measurement Equipment

The acceleration and deceleration rate of the train depend on the tractive force. When the wheels of the train slip on the rails, the torque is decreased to avoid the continuous slipping. This reason is that the tractive coefficient between the wheels and the rails has a peak at a certain slip velocity. But this adhesive phenomenon is not clearly examined or analyzed.Thus we have developed a new tractive test equipment. In this paper, we measured the tractive force with this equipment, and clarified the adhesive phenomenon. Then we proposed a new tractive force control and verified theeffectiveness of the proposed control scheme.