In this diploma thesis is documented an analysis and an approach of designing a self-propelled mobile reel mower with respect of general assumptions of industrial design. Thesis takes aim on a comparison of technologies of present manufacturers of garden equipment and proper choice and following application of technical solution and shape solution on a new product.

This master thesis contains modeling and nonlinear automatic control of an autonomous lawn mower. The vehicle shall be able to follow a magnetic field loop buried in the lawn on an arbitrary distance, including straddling. A unicycle model of the lawn mower has been derived based on previous work. The model holds for the assumption of non slip environment. Two diff erent control strategies have been implemented and evaluated in this thesis. One is based on feedback linearization  and with the feedback gain estimated using an LQ-controller. The other strategy is based on linearization at an equilibrium point  and also with the use of an LQ-controller. The only state that can be measured is the distance to the magnetic loop. In order to estimate the other states, an observer has been implemented using the linearized in an equilibrium point  model and a Kalman filter. The navigation of the autonomous lawn mower is performed using a magnetic loop buried in the lawn. The non-linearity of the magnetic field causes diffi culties when estimating the distance to the loop. One magnetic field strength corresponds to two distances to the magnetic loop. The nature of the magnetic field and the measurement noise causes the precision of the controller to be limited. The conclusion of this master thesis is that it is possible to navigate and follow the magnetic loop at a distance greater than 0.3 [m], but with overshoots during sharp turns. If the reference distance is smaller than that, the behavior of the robot will be oscillating when following the loop. The limitations of the controller performance is due to the lack of information which can be extracted from the measurements of the magnetic field.

Indiana University-Purdue University Indianapolis (IUPUI) / With the development of the electric mower, an electrical control system is necessary to drive the blades and the traction wheel. This thesis introduces an electrical deck control system. The system includes a high-powered deck controller and a permanent magnet synchronous motor (PMSM). A PMSM control model has been built in MATLAB/Simulink to verify and support the physical design. Three different PWM modulation methods have also been implemented and compared in MATLAB/Simulink. Furthermore, a model for the distribution and features of grass was built based on sampling of Google Street View images. A six-step pulse width modulation (PWM) control strategy was realized using a PIC33 embedded microprocessor. An enhanced closed-loop control system design was implemented to keep a constant blade speed in order to cut grass efficiently.

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2 pp. / Describes how to select the appropriate lawn mower to properly mow the species of grass at the correct height for high, medium, or low maintenance levels.

The main theme of this piece of work is to assess the influence of small mechanisation for maintenance of grass areas; therefore this work includes the description of grass areas as well as the overview of small mechanisation for maintenance of grass areas. Two types of mowers working on different principles of cutting were chosen to make a comparison. This work presents the results of measurement taken on 2 experimental grass areas treated by chosen types of mowers. There are results of monitoring of agrobotanical groups reported (coverage of grasses, the juncaceae, the cyperaceae, the clovers, and herbs) and coverage of grasses is graphically depicted in this work. Different results of grass coverage were statistically evaluated and compared just as the dry matter yields. Appropriate treatment of grass areas (mowing, supplementary seeding) as well as appropriate cutting system of small grass areas was recommended.

The diploma thesis based on the Analysis of factors influencing maintenance of lawns deals with maintenance of lawns, mowing machines used during maintenance, overview of factors that affect the performance and consumption of mowers in maintenance of lawns. In order to evaluate the efficiency of the mowers, the effects of selected factors were assessed, namely the size and shape of the plot, the character of the stand, the height of the mowing, the slope of the land and the influence of the mower operator.