| Aerial construction work platform is a kind of indispensable equipment in the building construction. The work platforms, such as scaffold, steel frame, portal frame, construction el-vator and various lift machinery, are widely used in our country today. These equipments have a lot of disadvantages as bellowing:a great deal of materials to setup, much more time to bui-ld, height limited and immoveable. Therefore, it is necessary to develop a convenient, effici-ent and safety work platform to replace the traditional platform.Aerial Work Platform (AWP), also called as Aerial working vehicle, is a new kind of mo-vable construction machinery which is used to transport workers and equipments to a specifi-ed height. On the basis of analyzing mechanical structure, hydraulic system, and performance of AWP, a scheme of AWP electrical control system was proposed in this thesis according to the requirements of safety use, movement operations and their logic relations. The main re-search content is as follows:(1) The structure of AWP machinery, the principle of AWP hydraulic system and the re-quirements of safety and protection were firstly investigated. Base on the investigation, the control and detection demands for AWP were settled.(2) The movements and their performances and the requirements of AWP safety use were discussed detailedly. Thereafter, a control system of AWP was developed by using a program-mable logical controller (PLC). In the control system, all movements were manipulated direc-tly with operation handles, and the PLC was used to detect the states of operation handles and the AWP working conditions in realtime.In the same time the PLC also output logical co-nstraints for every movement operation. This makes the platform work in reliable and ensures personnel safety for operator greatly.(3) A leveling method for AWP chassis balance was studied which uses a simple geo-metrical principle that three points ascertain a plane. We firstly choose three out of four out-riggers to setup an initial plane, the one with the smallest height is treated as control object which height is taken as control variable, then adjust the height to let inclination angle in one direction become 0°gradually. Secondly, another one with smaller height is picked as new control object, we adjust its height to make inclination angle in another direction become 0°with the same manner. As a result, we turn the AWP chassis to reach an expected plane.Keep-ing the inclination in two directions, we let down the other two outriggers on the ground and finish the AWP chassis leveling operation.(4)In order to improve the reliability of the AWP system, redundancy technology was applied in system design. A sensor with double angle and length detection circuits was chosen to measure the length and angle of telescopic boom as the AWP working. Moreover, an arbi-tration logic algorithm was presented to process two channel redundancy signals, which ensures the accuracy of measurement in AWP system.(5) An auto-leveling control circuit was developed for basket. When the basket inclina-tion exceeds 5°during the AWP working, we should perform the basket with manual level-ing manipulation. However as the basket inclination is below5°, the auto-leveling control circuit can drive the leveling machinery of the basket to turn its inclination below1.5°, then the basket is in expected level condition.
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