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The design methodology have been proved its effectiveness concerned to new products development, and due to the systematic approach it allows great variety of solutions and concepts developed in the early concept design phase. This paper shows two efficient methods in concepts generation, they are: the brainstorm and the morphologic chart. Both were successfully used and the result was a new concept of wheelchair motorization which the electric motors are activated only when the force applied over the propulsion ring exceeds a preset value. This new concept was registered at INPI as an invention patent.

The design methodology have been proved its effectiveness concerned to new products development, and due to the systematic approach it allows great variety of solutions and concepts developed in the early concept design phase. Axiomatic design was use to create collaborative strategies aiming to reduce the number of control strategies tests. Besides only one of required functions was developed and test each time. A wheelchair dynamic model was developed to test the strategies. At the end of the processes a role and complex control strategy was developed and only validation tests were need to apply the solution in wheelchair motorization.

The aim of this article is to compare three strategies for motorization control of a servo assisted wheelchair. A servo assisted wheelchair is new conception of a therapeutic wheelchair. The model used in this development is based on doubled bicycle model which driven force applied over the rear wheels and the steering over the front wheels. For this article three strategies were developed and simulated one “on-off” control, one rule control and a fuzzy control. The most appropriated strategy for the studied system was a rule control, because it has a best performance in terms of the system displacement.

The aim of this article is to study the dynamic behavior of a system composed by a child and a wheelchair during the propulsion with a servo-assisted motorization controlled with a logic fuzzy algorithm. The model correspond a vehicle with propulsion on the rear wheels, steering is on the front wheels. The wheels were modeled as rigid and a double bicycle model was used. The fuzzy controller will act over the system applying additional forces during the wheelchair propulsion looking for increase the user mobility and will be tested and evaluated bearing on mind the increasing of the system performance.

This paper studies the stability of a system and also its dynamical behavior during propulsion. The model was based on Newton-Euler-Jourdan equations. The resulting stability equation is general and establishes the velocity limit of the vehicle. This was modeled with propulsion on the back wheels and the steering on the front wheels. To establish the forces acting over the four wheels was used single-track model twice. It was determined equations for the transversal and longitudinal accelerations and for the rotation over the yaw axes of the vehicle. The contribution of this article is general equations for stability and dynamical behavior.