Block-matrix model of treelike actuator of walking robot is developed by considering external links imposed. This paper proposes an algorithm of formation of the mathematical model based on the use of matrices (4x4) and graph theory. The authors showed efficiency of its use for walking robots (by example of a bipedal walking robot).

The use of throttles as elements of control devices in hydraulic drives requires them to ensure the possibility of pressure dependence on the flow of the working fluid of the desired type. To establish this dependence it is necessary to know the area of the opening at the inlet of the throttling passage. However, the direct method to measure the actual value of this area resulting from the manufacture of the throttle channel is not always possible. The article presents the evaluation of the possibility of using the alternative method of determining the area of the entrance to the throttle channel of circu-lar cylindrical shape.

A study was made for the continuous flow of the working fluid through a cylindrical throttle channel (so-called “locking effect”). The flow of the fluid into the atmosphere and the change in absolute pressure at the inlet to the throttle channel ranging between 0.221 MPa and 0.24 MPa are studied. It was found that the pressure in the compressed section inside the throttle channel remains almost constant and equal to 4 kPa. A comparison is made of the experimental values of the flow rate determined for the same absolute pressure difference Δp in the separated and unseparated flow regimes. Knowing that the value of the flow coefficient μ in the zone of the existence of the “locking effect” can be determined from known data for the process of fluid outflow from holes with a sharp edge in a thin wall. Also, similar phenomena occur when fluid flows through small holes and slots in the guide, control and regulatory equipment of various hydraulic systems.

The paper presents the results of experimental studies of hydraulic drive with throttle control. The fluid flow is considered in a flat slit-like throttle channel accompanied by the appearance of cavitation phenomena. The comparison of the results of the calculation of flow compression rate, performed on the basis of the jets theory in accordance with the procedure proposed by Professor S.S. Rudnev, is presented in the paper together with the values ​​of the rate obtained by experimental methods. The study of the orifice coefficient for a flow with forming a closed cavity is conducted using an equivalent circuit.