Design of intelligent cleaning system for aeronautical ground light

Cui-li YU, Qing-ji GAO, Ping XU

(Robotics Institute, Civil Aviation University, Tianjin 300300, China)

Abstract: Aimed at the problems of the long time and high cost for manual cleaning of aeronautical ground light, an intelligent cleaning system of aeronautical ground light is designed. According to the material of the aeronautical ground lights, electromagnetic sensors are used to sense the lights. The angle adjustable cleaning probe is designed, and the cleaning vehicles is also designed, on which the cleaning probe, light sensors and the drying equipment are loaded. The single-chip microcomputer is used as the controller, and the control flow is given to realize the automatic detection, cleaning and drying of aeronautical ground light.

Key words: Aeronautical ground light, Cleaning vehicles, Cleaning probes, Control system

1 Introduction

The tire rubber left by aircraft when it lands, which friction with runway aeronautical ground lights, the air oil spilled when the aircraft glides on the runway, dust and dirt, pollutes the surface of the aeronautical ground lights [1]. As a result, the luminous intensity of aeronautical ground light is reduced, that has an impact on the safety of the aircraft operation [2- 4]. Therefore, it is necessary to carry out regular cleaning of the surface of aeronautical ground light at the airport [5].

At present, aeronautical ground lights is cleaned manually in the night after the aircraft suspension. This way has a low efficiency and the cleaning effect is not satisfactory, and it cannot meet the growing demand for civil aviation transport volume [6-7]. Abroad, semi-automatic equipment is also used for aeronautical ground lights cleaning work in developed countries, such as the high-pressure water jet, the large cleaning vehicles, and some high-tech auxiliary cleaning equipment [8-9], which are also urgently needed to be improved on the cleaning efficiency. According to the characteristics of aeronautical ground light, the intelligent cleaning vehicles and cleaning probe of the aeronautical ground light are designed in this paper, to realize the automatic detection of the aeronautical ground light, automatically cleaning and dries, which improves the efficiency of the cleaning for aeronautical ground light.

2 The structure design of intelligent cleaning system for aeronautical ground lights

2.1 Embedded aeronautical ground light

Embedded aeronautical ground lights are widely used in airport runways and taxiways to provide the necessary guidance information for aircraft take-off, landing and sliding. In this paper, an intelligent cleaning system is designed for embedded air-supporting lamps. The appearance of the embedded aeronautical ground lights is shown in Fig.1. The embedded aeronautical ground light is circular, the height of the upper cover protruding ground is no more than 1.5cm, the two sides lens of the light tilt arranged in the embedded metal shell, its lens surface and the ground angle is about 40°[10]. The tilt angle of the lens makes it impossible for the general cleaning vehicle to clean it effectively, and the groove structure of the light surface also the contaminants to gather here easily. Therefore, it is necessary to design the angle adjustable cleaning probe based on the characteristics of embedded aeronautical ground light, which help probe aligned with lens of the light when it is being cleaned and can greatly improve the cleaning effect.

Fig.1 The embedded aeronautical ground light appearance

2.2 The structure design of aeronautical ground light cleaning system

There are aviation oil, paint, rubber, water stains and dust on the lens of embedded aeronautical ground. The automatic cleaning system of the aeronautical ground light designed in this paper can sense the light, then, choose the right detergents to carry on the automatic cleaning work according to the surface pollutants of the light, and carry on the drying treatment to the light. Correspondingly, the intelligent cleaning system of aeronautical ground lights designed in this paper can be divided into cleaning vehicles, cleaning probe unit, and control unit. The overall structure of the intelligent cleaning system for aeronautical ground lights is shown in Fig.2.

Fig.2 The structure of intelligent cleaning system for aeronautical ground light

(1) Design of cleaning vehicles

The cleaning vehicles carries all the components of the cleaning system and provides working support for the light cleaning probe unit. The cleaning vehicle is mainly composed of vehicle frame, longitudinal track, transverse track, stepping motor and connector. The cleaning vehicle frame, which is made of aluminum profiles, is equipped with the track and stepping motor on the longitudinal and transverse beams respectively. So the cleaning probe can be moved in the front and back, left and right directions by controlling the movement of the longitudinal stepping motor and the transverse stepping motor. In addition, the cleaning vehicle is also equipped with a moving wheel for easy installation on other power mechanisms.

(2) Design of cleaning probe structure

According to the function and structure of the cleaning system, the cleaning probe is divided into an angle adjustment module and a cleaning module. The structure of the cleaning probe is shown in Fig.3.

Fig.3 The cleaning probe structure

The angle adjustment module is mainly composed of four push-rod motors, which are mounted on the cleaning vehicles by the pin shaft, the connecting parts, etc. Four push-rod motors are divided into two groups. The two push-rod motors of each group are controlled in parallel. The angle and distance between the lower plate and the ground can be adjusted by the expansion and contraction of the two sets of push-rod motors, so that the brush is better vertically close to the lens surface of the light to enhance the cleaning effect.

The cleaning module is mainly composed of a brush head, a nozzle, a gear, a bearing and a DC motor. The six brushes are divided into two groups, three in each group, and the brush in the middle of each group is coaxially connected with the DC motor, and is connected with the two brushes on both sides by the gears and rotating shafts, so that one DC motor drives a group of brush heads to operate. The steering of the middle brush in each group is opposite to the steering of the two adjacent brushes. The three gears of each group adopt standard parts, and the number of teeth is equal, that is, the transmission ratio is 1, so the rotation speeds of the three brush heads are the same, and the resistance between the bristles rotates when they fly. The nozzle adopts a fan-shaped nozzle [11]. Under the high pressure, the liquid sprayed by the fan nozzle has a great impact force, which can enhance the cleaning effect, use less liquid, and save resources.

3 Design of intelligent cleaning control system for aeronautical ground lights

The intelligent cleaning system control unit of aeronautical ground lights mainly includes a microprocessor module, a light positioning module, a motion control module, a water pump and gas pump driving module. The control schematic of the intelligent cleaning system for aeronautical ground lights is shown in Fig.4. The microprocessor module is the core of the whole control system, single chip microcomputer is used in this paper as the controller, which is responsible for receiving user commands and light positioning information, and controls the operation of the motion module, water pump and drying device.

Fig.4 The control schematic of intelligent cleaning system for aeronautical ground lights

The light locating module adopts an electromagnetic sensor, and the electromagnetic sensors are arranged in a row in a long slot according to the equal spacing. When the cleaning vehicles travels, the light locator is lowered to a reasonable position to facilitate the sensing of the locating light, and the light locator is stowed up during the cleaning system process, which make it is easy to clean the lights.

After receiving the high-level signal from light locating module, the microprocessor controls the stepping motor, so that the cleaning probe moves horizontally and longitudinal guide rails in the cleaning vehicle, and finally aligns the light. The cleaning of the light is realized by the rotation of the cleaning brush controlled by the DC motor. To improve the cleaning effect, the microprocessor controls the expansion and contraction of the two sets of push-rod motors, keeping the angle between the cleaning probe and the light lens at 90°, and cyclically changing the cleaning area. In combination with the switch control of the water pump, the cleaning of the light is accomplished, and finally the air pump is turned on for drying to complete the cleaning process.

4 Software Design of intelligent cleaning system for aeronautical ground light

During the movement of the cleaning vehicles, the embedded aeronautical ground light is sensed by the light detection module, and the cleaning probe is aligned with the light by controlling the horizontal and vertical stepping motors. The staff selects the appropriate cleaning agent according to the surface contamination of the embedded luminaire, and the water pump is turned on by the control unit automatically for cleaning work. The software flow chart of the intelligent cleaning system of the aeronautical ground light is shown in Fig.5.

Fig.5 The control flow chart of intelligent cleaning system for aeronautical ground lights

5 Conclusions

In this paper, the cleaning vehicles and cleaning probe of intelligent cleaning system for aeronautical ground lights are designed, and the control system and software to realize automatic cleaning and drying are designed. The intelligent cleaning system of the aeronautical ground light is reliable in detection, angle adjustment and cleaning. The design of intelligent cleaning system for aeronautical ground lights provides the basis for the application of the system, which can meet the high cleaning efficiency of aeronautical ground light.