Programming the trajectories of machine-tractor units

The control of trajectories of self-propelled agricultural vehicles and machine and tractor units (MTU) is carried out according to certain programs stored in memory of the tractor driver or in the system of autonomous driving. In the tractor driver’s memory, the programs are laid down at the stage of studying and mastering the specialty, and are specified when receiving a task to perform a specific job. A common opinion about programming a trajectory following a previous MTU passage is erroneous as the trace is the coordinate line used to bind the desired trajectory to the terrain. The quality of trajectory driving depends on the tractor’s driver, his experience and qualification but not the system of coordinates. Similarly, for autonomous driving of MTU the possible driving programs must be put into the autonomous system at the design stage, and be specified with settings before work start. The quality of autonomous driving is defined by technological level of a system of autonomous driving, which integral part is the coordinate system. There are various ways to define system of coordinates. The most promising of them is to stationary reference points in the form of underground current-carrying wires. Such systems have the high definition, universality, autonomous waymarks, noise stability and long-term stability. To realize all the advantages of coordinates systems set by underground current-carrying wires it is necessary to determine the location of MTU by point-to-point differential and amplitude method by a projection of magneto-field vector to a cross axis of the tractor or a single-point two-level amplitude and phase method. High programming accuracy is achieved by means of current-carrying wires made by commutable ones, power supply of adjacent wires by counter currents and creation of navigation magnetic field by currents of three adjacent wires, where the middle wire is a contact line. The high definition of the guidelines and the noise immunity of the algorithms allow determining both the path mismatch and the direction of the longitudinal axis of the tractor and the direction of the velocity vector as well. Introduction of these parameters into the control law of steering mechanism allows increasing the stability of systems of autonoumus driving and accuracy of trajectories control of working bodies of technological machine tools.