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As an essential means of transportation in the modern people's living and production places, the number of elevators in use and the number of new increases are constantly rising. The safe operation of elevators has attracted strong attention from the society and people. The operating principle of drag force driving elevator is to utilize the friction between wheel groove and the wire rope to drive the wire rope, so that the elevator car and counterweight block move up and down. Elevator upward braking check is an important test stipulated by the national inspection regulations, the test results can reflect the braking performance and traction capacity of the elevator. If the elevator cannot be stopped reliably under the upward emergency braking condition, there may be a risk of crashing to the top without control, thus causing serious safety accidents. There are two situations of failure for the unreliable stopping, of which one is the insufficient braking force, the other is the insufficient drag force. When the drag force is sufficient but the braking force is insufficient, the braking wheel will slip but the drag wire rope won’t [9]. There will be an elevator sliding due to the elevator car (or counterweight block) weight and drag wheel and elevator car cannot be stopped. When the stopping force is sufficient but the drag force is insufficient, the drag wheel can be stopped but there will be a sliding between the drag wheel and wire rope, the elevator car cannot be stopped, either. To ensure the safe operation of the elevator the upward braking drag investigation should be carried out frequently during the operation of the elevator. The existing testing methods of upward braking are mainly wire rope marking and visual testing. The current inspection methods all have evident defects that the error of the measurement data is large and the misjudgment of the inspection results easily appear. In this paper, an automatic testing system for elevator upward braking check is studied, which is composed of weighing device, data collection device, control device, central processing unit and alarm device. It has the advantages of accurate measuring data, simple operation and small installation difficulty.
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