Cooperative Transport Systems Research Articles

Control of A Cooperative Transportation System with Two Car-Like Mobile Robots Based on Chained Form (Experimental Verification of Its Open Loop Control)

We have developed a cooperative transportation system with two tricycle mobile robots which are kinematically equivalent to car-like mobile robots, and we have verified the validity of an open loop control method based on chained form for the cooperative transportation system using the developed experimental apparatus. A mechanical feature of the developed tricycle mobile robot is that it is capable of controlling its single-steering wheel angle at high precision since it steers the single-steering wheel by a zero backlash spur geared motor. Another mechanical feature of the tricycle mobile robot is that it has a motor with a differential capable of driving its two rear wheels without slipping them, i.e., without spinning or dragging one of the rear wheels, when cornering. These features mean that the motion of the tricycle mobile robot is described by its kinematical equation precisely, and the controlling accuracy of the motion of the tricycle mobile robot is high enough to examine the validity of the open loop control method experimentally. We have performed a cooperative transportation task in which the two tricycle mobile robots trnsport a carrier cooperatively without changing the carrier orientation. Such task cannot be performed by a traditional single-trailer system. The validity of the open loop control method is verified by the experimental examination.

2P2-E20 小型全方位移動ロボットによる群知能に関する研究 : 第二報 : Visual Programming環境を用いたプログラム開発

The researches on swarm intelligence have been actively investigated using many robots. Cooperative transportation, distributed sensing, and collision avoidance system using communication, research topics of the swarm intelligence. In this paper, a platform of small mobile robots to examine swarm intelligence, named "With" is controlled by visual programming environment. And, we examined the motion control to use visual programming "iCONNECT".

Cooperative transportation system for humanoid robots using simulation-based learning

In this paper, an approach to the behavior acquisition required for humanoid robots to carry out a cooperative transportation task is proposed. In the case of object transportation involving two humanoid robots, mutual position shifts may occur due to the body swinging of the robots. Therefore, it is necessary to correct the position in real-time. Developing the position shift correction system requires a great deal of effort. Solution to the problem of learning the required behaviors is obtained by using the Classifier System and Q-Learning. The successful cooperation of two HOAP-1 humanoid robots in the transportation task has been confirmed by several experimental results.

Characterization of the choline carrier of Plasmodium falciparum: a route for the selective delivery of novel antimalarial drugs

AbstractNew drugs are urgently needed to combat the growing problem of drug resistance in Plasmodium falciparum malaria. The infected erythrocyte is a multicompartmental system, and its transporters are of interest as drug targets in their own right and as potential routes for the delivery of antimalarial drugs. Choline is an important nutrient that penetrates infected erythrocyte membranes through the endogenous carrier and through parasite-induced permeability pathways, but nothing is known about its transport into the intracellular parasite. Here we present the first characterization of choline transport across the parasite membrane. Transport exhibits Michaelis-Menten kinetics with an apparent Km of 25.0 ± 3.5 μM for choline. The carrier is inhibitor-sensitive, temperature-dependent, and Na+-independent, and it is driven by the proton-motive force. Highly active bis-amidine and bis-quaternary ammonium compounds are also known to penetrate the host erythrocyte membrane through parasite-induced permeability pathways. Here, we demonstrate that the parasite choline transporter mediates the delivery of these compounds to the intracellular parasite. Thus, the induced permeability pathways in the host erythrocyte membrane and the parasite choline transporter described here form a cooperative transport system that shows great promise for the selective targeting of new agents for the chemotherapy of malaria. (Blood. 2004;104: 3372-3377)

Analyses on future urban transport and freight transport measures from a viewpoint of E-commerce

We examined effects of E-commerce on urban road traffic and environment in the future. We can point out that effects depend on various conditions of & commerce companies and E-commerce users. We evaluated various measures on freight transport using traffic simulation in the condition that E-commerce becomes popular. Results indicated that co-operative delivery systems are effective for decreasing total costs. The large truck ban can improve the environment, but it increases costs of companies, and co-operative freight transport system can alleviate them.

A Path Planning Using Bezier Curves for A Cooperative Transportation System with Two Car-Like Mobile Robots

This paper presents a novel path planning methodology using Bezier curves for a cooperative transportation system with two car-like mobile robots. We first transform the kinematical equation of this transportation system into two-chain, single-generator chained form in a coordinate system where a path is a curved line axis and a straight line perpendicular to the tangent of the path is another axis. The carrier of the transportation system can follow any path as long as its curvature is two times differentiable. The orientation of the carrier is uniquely determined according to the orientation of the tangent of the path. We secondly set the path to be a Bezier curve and we arrange the controlling points of the Bezier curve based on the working environment of the transportation system, e. g., in order for it to avoid collisions wit obstacles. The validity of this path planning methodology is supported by computer simulations.

Investigating the Effects and Profitability of Urban Co-operative Freight Transport Systems Considering Customers Location and Systems Type

This paper focuses on the effects and profitability of urban co-operative freight transport systems. Forecasted VRPTW based mathematical models were used for investigating the influence of the location of customers and different types of co-operative freight transport systems on the effects and financial viability of such systems. Applications of the models to an urban goods delivery revealed that co-operative freight transport systems cannot be profitable if the location of customers is widely dispersed within-urban areas and considerable benefits can be gained by implementing carriers-led co-operative freight transport systems without the leadership of public sector.

A Conversion of a Cooperative Transportation System with Two Car-Like Mobile Robots into Two-Chain, Single-Generator Chained Form and Its Steering

This paper presents a novel methodology for steering a cooperative a transportation system with two car-like mobile robots coupled together by a carrier. The system is a three-input seven-state drift-free nonholonomic mechanical system. The three control inputs are the moving velocity of the first mobile robot and the steering angular velocities of the two mobile robots. The seven states are the positions of the first mobile robot along the x- and y-axes, its steering angle, its orientation, the orientation of the carrier, the steering angle of the second mobile robot, and its orientation. We first convert the system into two-chain, single-generator chained form, based on a differential geometrical approach. We secondly show a control method of the system by polynomial inputs developed in such chained form. The validity of this conversion and control method is verified by computer simulations performed on driving this cooperative transportation system into a garage.

2台の車両型移動ロボットから構成される協調搬送システムの経路追従フィードバック制御法

2台の車両型移動ロボットから構成される協調搬送システムの経路追従フィードバック制御法

Modelling Co-operative Freight Transport Systems for Investigating Their Effects and Profitability

Co-operative freight transport systems have the potential for solving many of urban traffic problems. This paper presents a co-operative vehicle routing and scheduling model with optimal location of logistics terminals for investigating the effects and materialisation of co-operative freight transport systems. Applications of the model to an urban goods delivery showed that introducing co-operative freight transport systems could lead to a substantial reduction in delivery cost and total travel time within the whole road network, while the profitability of the co-operative freight organisation depends on the area size and the number of customers.

An evaluation methodology for city logistics

This paper presents a methodology for evaluating city logistics initiatives using a dynamic traffic simulation with optimal routing and scheduling. This methodology was applied to a test road network. The performance of three city logistics initiatives, advanced routing and scheduling systems, cooperative freight transport systems and load factor controls were assessed in terms of total costs and CO2 emissions by pickup/delivery trucks operations within the network. Results indicated that these initiatives were not only effective for reducing total costs, but also for CO2 emissions. The methodology presented here allows city planners to quantitatively evaluate city logistics initiatives.