A mathematical model of the manipulator drive with a stepper motor is developed in the form of inductance equations, which is a source of reactive moment, inertial moment equation and angular velocity. Stepper motors work in the drives of manipulators with continuous movement, when the control action is given by a sequence of electrical pulses. The block diagram of the speed and current control loop of the stepper motor, given by the operator, is calculated in the computer (full step, direction, correction value for reverse speed, acceleration braking), the data is sent to the controller, in the controller the signals pass through the hard logic circuits and are sent to the driver. The stepper motor driver board generates a signal that is fed to the stator windings of the stepper motor. The results of mathematical modeling in MATLAB & Simulink are presented. The dependences of the oscillatory process of the system in the transients of the stepper motor, which are oscillatory in nature, are obtained. A comparison of the results of theoretical modeling of the operation of a step drive with experimental studies is given. As a result of the simulation, additional dynamics arise in the armature current circuit, however, at the point of the nominal mode, it does not significantly affect the angular velocity regulation processes, that is, the speed regulator provides its astatic regulation under the action of a constant load moment.

While developing the Arctic territories, the use of mechanical equipment, adapted to work at low temperatures, is required. The power element of hydraulic machines is a hydraulic fluid, which, under different ambient conditions, changes the viscosity-temperature properties. With decreasing temperature, the viscosity increases. The hydraulic fluid lubricity of the rubbing surfaces of the hydraulic drive elements is declining. On rubbing surfaces, the oil film strength decreases, which leads to its rupture. A hydraulic circuit of the hydraulic drive is proposed, containing an additional adjustable throttle. When throttling the working fluid, the thermal energy releases. The process of throttling the working fluid is described by differential equations. To simulate the proposed system, a dynamic closed-loop hydraulic model was compiled using MATLAB&Simulink. Modeling the hydraulic drive made it possible to obtain the time dependences of the working fluid pressure as it leaves the throttle. The obtained dependences by mathematical modeling made it possible to determine the effect of the differential pressure on the throttle on the fluid flow rate, as well as the dependence of the decrease in the liquid flow coefficient on the differential pressure. The use of a throttle hydraulic actuator with a closed-loop hydraulic circuit ensures stable temperature conditions.