-90 108 mm/sec; 238 N; 0,79 sec. 79 mm/sec; 340 N; 0,91 sec.

If we choose diameter of piston 50 mm the time of one movement is less than 0,92 sec for moving out and 1,07 sec for moving in, dynamic braking load limit in ranges 170 … 371 N, velocity in the moment of contact of piston and the cap is less than 108 mm/sec – that is acceptable for such kind of   VMMR.

Thus, results of computer modeling testify the possibility to achieve the high-speed and smooth movement of VMMR drives using the mechatronic electro-pneumatic drive of longitudinal movement. The results of this research were successfully used in the development process of real VMMR sample, which is capable to transfer the object with weight up to 50 kg.

6. Summary and conclusions

We see that the possibility of cushion systems of standard pneumatic cylinders limited. These systems can’t provide required absence of shocks in the end of the stroke and smoothness of movements when they integrated in vertical movement’s mobile robots  (VMMR).

The offered structure and principal diagram must be used for the development of high-speed electro-pneumatic drives for vertical motion mobile robots with high  smoothness.

These drives represent mechatronic systems and allow making flexible multistage  braking  in  the  end  of the stroke; they allow achieving high-speed movement at simultaneous restriction of dynamic braking loads  and essential decrease of velocity of the piston at the end of a  stroke.

Diameter of the cylinder in such drives must be chosen not only with considering of the  weight  of  mobile platform, but with analyzing of dynamic issues of movement with massive  object.  For  the  considered  vertical motion mobile robot dynamic braking loads must be less than 500 N – this can be achieve only with using of cylinder with piston not less than 50 mm.

The using of flexible system of throttles for multistage braking together with additional reservoirs and absence of the cushion seal allows reducing the frequency of oscillation of the speed in the braking zone. That provides reducing in several times of dynamic braking loads with comparison with standard cushion (braking) systems integrated in cylinders.

The computer simulation program represents effective means of development of high-speed electro-pneumatic drives for massive objects. It helps to choose the structure and parameters of the drive. It is strongly recommended in the process the VMMR electro-pneumatic drives development for calculating of effective diameter of the piston, number of braking stages, flow rates of throttles, positions of sensors, supply pressure and for testing of computer control algorithms.

The offered structure and principal diagram will be used for the development of the real prototype of the high- speed electro-pneumatic drive for vertical motion mobile robots for making an experimental researches. These experiments will show us the issues of the using of offered math models, methods and computer program. That will help us to modify and improve all of it. The math model is also required detailed description of the friction force and the thermodynamic processes in the compressed  air.

The second important part is that the solution, described in this article for vertical motion mobile robots  will become the basis for developing of universal method for creation of high-speed electro pneumatic drives for smooth movement of massive objects. Having of such type of method in software realization will dramatically reduce the time of developing of such kind of pneumatic  drives.