Patent ID: 8079433
Filing Date: 2011-12-20
Classification: A01D,B60K,B62B,B62D

Abstract:
1. A self-propelled machine, comprising: a speed control mechanism configured to control a speed of movement of the self-propelled machine; a direction control mechanism configured to control a direction of movement of the self-propelled machine; a retractable and extendable line mounted on the self-propelled machine such that the line is under tension in a retraction direction when the line is extended from the self-propelled machine; a line extension monitoring device configured to monitor a length of extension of the line; a speed controller connected to the line extension monitoring device and to the speed control mechanism and configured to control the speed control mechanism to control the speed of movement of the self-propelled machine in response to the length of extension of the line to maintain the length of extension of the line at a selected length; a line angle monitoring device configured to monitor an angle of the line with respect to the self-propelled machine; and a direction controller connected to the line angle monitoring device and to the direction control mechanism and configured to control the direction control mechanism to control the direction of movement of the self-propelled machine in response to the angle of the line to maintain the angle of the line at a selected angle wherein the direction controller is configured to control the direction control mechanism to turn the self-propelled machine to the right in response to a displacement in the angle of the line to the left and to control the direction control mechanism to turn the self-propelled machine to the left in response to a displacement in the angle of the line to the right.