| 摘要 |
A digital map drawing system includes a horizontal support device (200) composed of a first bottom plate (210) seated on the ground surface and a lifting tube (220) seated on the first bottom plate (210) so that a plurality of chambers may be partitioned and separated with the same intervals by a separating part (221) thereby the air can come in and out, and if a position finder (100) is disposed to be tilted, a state of the position finder (100) standing erect in an upright position is maintained by injecting the air, or a state of the position finder (100) standing erect in an upright position is maintained automatically by having the horizontal support device (200) to be further equipped with: an air pump (241); a plurality of three directional valves (243, 244, 263, 264) installed at front end and rear end of the air pump (241); a branching line (245, 265) branched from first and second circulatory lines (242, 262) between the three directional valves and connected to each chamber of the lifting tube (220); an air supply/discharge unit (240) installed in the branching line (245, 265) and including opening and closing units (246, 266) to open and close airflow to each chamber respectively; and a control part (250) to control the air supply/discharge unit (240), and by controlling the three directional valves and the opening and closing units so as to shrink or expand each chamber of the lifting tube (220) selectively. |
