The bodies of trucks or trailers are provided with automatic folding shutters to ease the discharge of the transported materials. Typically, these shutters are powered by mechanisms that have active motor groups such as RRTaR or RR-RR-RTaR (i.e. motor dice or triads) and passive motor groups such as RRR, RR-RR-RR etc. If the technological forces are high and the relative speeds between the elements forming the steering coupler are small, the motor groups are formed by rigid bars and hydraulic cylinders. If relatively high gear ratios are required, then pneumatic cylinders may be used. If required relatively high speeds in the driving couplings, then you can use pneumatic cylinders. This paper presents structural and kinematic analysis of a shutter from a trailer used to transport bulk agricultural products, discharge towards the back. For the kinematic analysis of the folding shutter mechanism, computational procedures written in the Matlab syntax are used. The results of the calculations are presented in tabular and diagrams. After the cinematic analysis of the mechanism, it is possible to perform its cinetostatic analysis, i.e. the determination of the reactions from the kinematic couplers, as well as the hydraulic force in the hydraulic cylinder. Results can be used for the dimensional verification of the chosen elements.

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Based on the relative positions of the parts to be assembled, positions imposed by the technological process of insertion, the conditions required to perform a predetermined operation have been defined. The relations that express the relative positions and orientations of the axes of the parts to be assembled have been determined. These expressions enable the establishment of the functional requirements imposed on the robot. We have taken into consideration the influence of robot accuracy on its positioning and orientation repeatability.

This paper deals with the analysis of the mechanical system of a self-propelled vehicle on the tires able to move on an uneven ground whilst his platform stays horizontally. It is question to simulate the movement of a desmodromic robot which moves in an environment represented by a 3D surface. The robot has a mechano-hydraulic system which is able to modify the geometry of chassis in the aim of maintaining the platform always at horizontal while in movement, no matter the soil configuration (of course between some limits).The horizontalisation mechanism with the rolling train hydraulically driven presents some difficulties because of the non holonomic constraints of the wheels ([1, 2]). In order to make the application of the multipoles theory in the structomatical model must be introduce some simplifications in the contact joint. Thus, the non holonomic joints are presented like gamma active joints (with the condition of controlled rolling/skidding).This is an extension of the general principle of mechanism formation ([3]) according who any mechanical structure can be broken in genes upon an unique formula (the genetic code of the mechanism).Because of the complexity of the calculus the study of mechanism was divided in a few chapters: geometrics, structomatics, kinematics, kinetostatics and dynamics etc. The uttermost important and difficult part is the kinematical model because of the non-linearity of the equations. This article presents the first two items; the others will be the matter of future papers.

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