1 Introduction
In recent years, with the rapid development of Chinese industry, cleaner production and sales volume has increased significantly in China's market has great vitality. With the social progress and development, people's material and spiritual improvement of the quality of the urgent need to clean from the heavy work out. Thus the birth of a service-oriented home cleaning robots, mobile robots will be cleaning technology and the organic integration of technology to achieve the family hotels, office buildings and other indoor environment clean and semi-automatic or fully automatic, so has a broad market prospects. In this paper, cleaning robots, on the domestic and foreign research and its key technologies are introduced, and the development of cleaning robots in the near future a number of issues were discussed.
2 Cleaning robot research at home and abroad
In Europe America and Japan and Other developed countries, the development of cleaning robots earlier, is also a wider range of applications, the last two years, has developed a wide range of market-oriented intelligent cleaning robot.
2.1 Japan produced vacuum cleaner
Japan some company to promote the family in 2002 to use vacuum cleaner robot's trial seize the opportunity [1] in the first half of the year. This robot may when according to the room shape the floor condition, the quantity of refuse carries on the automatic cleaning the work, first along the room all around will walk a memory room shape, then, while avoids the obstacle by vertical, the crosswise way back and forth to move carries on cleanly after the clearing completes, the automatic stopping This vacuum cleaner robot equipment has 50 sensors, but on the other hand on the one hand walks automatically carries on the cleaning. It uses the light and the ultrasonic wave range sensor, the feeling presses the sensor to avoid the obstacle; Built-in has the rotation sensor, uses for to control walks the posture maintains decides marches forward the direction; Has installed the rudder sensor, may examine marches forward the direction error which produces as a result of the rug pattern influence, even if therefore, in the shop has on rug's floor also to be able the straight line advance. In addition, this robot in vivo also installs has prevents heat source and so on dropping variance sensor which, sensation warming stove from high place and so on. Stair rolls down thermal seniors, to examine own receives the external force size definite weight sensor and the skid resistant sensor, the examination increase power load sensor. It may most little maintain with the ordinary obstacle 10 cm the distances but when surveys the heat source, will handle jointly with the heat source will maintain at least 50 cm the distances. Its contour size for wide 292 mm, long 367 mm, high 265 mm, heavy 9.8 kg, the maximum traveling speed is 30 cm/s. When the sensor survey on floor's trash, will enhance the suction to usual15 times, simultaneously the traveling speed drop will be 15 cm/s, will carry on the cleaning carefully. Will not be having trash place by the 30cm/s speed migration the suction also 1O reduce, a charge may work 55 min will sweep clear 80 m2 the rooms, will vacuum the power is 90W.
2.2 Australia's V4 vacuums robot
Australia some company also to develop may go automatically and clean the room the V4 robot. This kind of completely automatic vacuum cleaner surface is smooth, the volume is very small, assumes the circular, the built-in acquisition radar, may search in each kind of room each, will not collide the furniture or other obstacles. Micro processes the small computer to cause it have is turning to roof pinnacle place can survey the direction, choice route of advance's ability. So long as place the completely automatic vacuum cleaner in the ground, it then may start to work automatically. Its acquisition radar can survey's away from the recent wall, is being suitable the first wall attracts floor dust the foreign matter all around; Then back and forth moves anomalous again in room other positions, and can before the close obstacle changes rapidly. Should vacuum the robot, because 360°has provided the obstacle sensor in main engine's periphery, therefore may cleans the ground during the examination wall and obstacle; After cleaning the place which may go, robot on automatic shut-off power source. No matter the room contour and the area size, the
ARNA guidance algorithm guidance robot all not covers up the region movement in any room to carry on the clearing in all directions, because robot guidance along room periphery, therefore it must found her spatial reference diagram, doesn't the robot need any programming "where to teach it to go to". This robot simplicity of operator only has 3 buttons：Starts the conclusion as well as the suspension so long as the people in laid aside simply in needed to sweep clear in the region or the room(this kind of completely automatic vacuum cleaner robot was very light, a hand might easy take up it), pressed down starts the button then.
2.3 Swiss trilobita vacuum cleaner is small “the trilobita”
Is Switzerland develops the production the completely automatic vacuum cleaner. Is small “the trilobita” high 13cm, diameter 35cm, the surface is smooth, assumes the circular, the built-in acquisition radar, may survey rapidly and avoids the table leg, the glassware, the pet or any other obstacles. Once micro processes the small computer to distinguish these obstacles, it may choose the route, and makes to the entire room judges and calculates, guaranteed that the room each corner is swept clear. And so on some do not have the natural barrier place in the staircase stair, so long as has magnet, will be small “the trilobita” then not to surmount. After being small “the trilobita” starts the start, I vivo acquisition radar can survey is away from the recent wall, is being suitable the first wall attracts floor dust and the foreign matter all around, it then can survey like the entire room the pattern, calculates time which the cleaning entire room needs. So long as a close obstacles, it will then establish the line of march, will not leave out each corner. Is small “the trilobita” attracts brushes installs the Chinese dress to have a patent design pulley, may cross the electric wire or the rug edge, is not impeded. When power source insufficiency, will be small “the trilobita” to return to charge automatically Booth to charge voluntarily. If this time room did not have the cleaning to finish, is small “the trilobita” to have the memory function, after sufficient good electricity, return to the original position to continue to vacuum.
2.4 American Rumba (Roomba) vacuum cleaner
By the American some institute artificial intelligence laboratory development’s wisdom automatic vacuum cleaner, the utilization artificial intelligence revolution and the guidance detection technology, cleans each inch floor intelligently, the real suction hole which and revolving matching is in sole possession of brushes, the clean effect is specially good. By the American TIME evolution was in 2002 one of coolest inventions. So long as presses down the switch, the Roomba completely automatic will assign the region to vacuum cleans, bumps into obstacle servo-assisted steering, will meet the staircase also automatically to detect cannot fall down, the special real suction hole, revolving will brush with revolving side brush the design, regardless of will be the rug or the floor, clean will be very convenient. Highly only some 10 cm, diameter 34 cm Roomba may with case sneak under the bed bottom or the sofa carries on cleans. The Roomba pattern is by mathematics operation idea design movement route. After Roomba start, will follow the spiral-shaped route revolution, by the helix revolution way which will expand gradually covers the space, when will bump will touch the wall or the furniture and so on large-scale obstacle, its special obstacle induction regulator can resist the wall surface protection fuselage not to receive damages, Roomba along the wall or the furniture advance, by now the body side hair brush sweeps into the corner perhaps the furniture edge sully dust detritus in the vacuum cleaner. Have swept clear part of space after the wall or the furniture, Roomba will transfer a 90°direction and sweeps the room according or the above route another head, was so alternately redundant, the screw revolution route to be possible back and forth to attract the room, the cleaning finishes namely the automatic stopping. This only heavy 2.5Kg, selects the charge method the vacuum cleaner convenience to be practical, the selling price is only 200 US dollars, already went on the market in Europe and America.
2.5 Domestic present situation
Domestic also started the related research development work at present, specially was moving robot’s movement plan and the control aspect has achieved certain achievement, vacuumed the robot for the research developed the omni-directional motion ground cleaning robot, this robot’s control system could explain the remote control signal accurately, and to organism issuing working order, momentarily received “the eye”(i.e. infrared light electric switch and supersonic sensor) the sensation four direction exterior barrier information, and requested the robot to make straight line or to change the movement according to the above, marched forward, it did not stop rotates the floor to brush, filled in “the stomach” completed the ground in dust, this kind of robot one time charged works sustainably for a half hour, had the intelligent power source management function, lengthened the running time, the average each minute running speed is 15m. in addition, should vacuum the robot to use the open style robot control structure, realizes the hardware to be possible to expand, the software to be possible to transplant, may to integrate, enables the robot to have the better function compatibility as the service carrier. At the same time, other colleges and universities to moved vacuum the robot also to do the massive research work, has made many progresses.
3 Vacuum robot’s key technologies
A idealization to vacuum the robot assembly system to be usually composed of four parts: the shifting mechanism, the sensation system, the control system and vacuum the system. The shifting mechanism is vacuum robot’s main body, had decided vacuum cleaners’ movement space, uses the wheeled organization generally; the sensation system uses the ultrasonic wave distance gauge, the contact and the close sensor, the infrared sensor and the CCD camera generally and so on; along with the recent years computer technology, the artificial intelligence technology, the sensing technology as well as the motion robot technology’s rapidly expand, vacuumed the robot control system’s research and the development has had the solid foundation and the good prospects for development. Vacuums robot’s control and the working conditions often is indefinite or changeable, must therefore give dual attention to the security reliability, the anti jamming as well as understand the environment through the suitable modeling method, obtain the environment more information, in recent years indicated to intelligent robot’s research, regarding the work in the multiple structure environment’s independent- like migration robot, must further enhance its independent degree, mainly depends upon the pattern recognition and the intelligence method, but also needs to further develop the overall situation model, thus gains the overall situation information influence big key technologies is : the multi-sensor fusion technology, vacuum the technology, the Chinese Journal of Power Source and so on.
3.1 Way plan technology
The way plan is the working conditions information which arrives according to the robot sensation, according to some kind of optimized target, plans one in the initial station and the target point with the environment barrier non-collision’s way, and realizes must sweep clear the region the reasonable complete way cover, its essence is moves in the robot rate process the guidance and evades bumps. The robot working conditions are different, divide into the static structurization environment, the dynamic sixth branch to know the environment and the dynamic indefinite environment. Since the 1970s research, has moved robot’s way plan to be different according to the robot gain environmental information way, divides into three type[3] approximately: ①Based on the model way plan, mainly processes the structurized environment, the plan method has the grid law ,to be possible the view law, the analysis sites law and so on; ②Based on the sensor information’s way plan, mainly uses in the non-structurized environment, overcomes the factor which the environmental condition or the shape are unable to predict that the method has the artificial potential field law, the determination grid law and the fuzzy logic algorithm and so on; ③behavior based mobile robot path planning is the light mobile robot path planning problem for research in the new trends, is the navigation problem is decomposed into many relatively independent unit that acts primitives such as collision avoidance, target tracking, guidance. With the development of computer technology and the development of sensor technology, multi-sensor integration and information fusion technology in intelligent robot has obtained the widespread application, unstructured environment, mobile robot is the robot technology development, based on multi-sensor information fusion for mobile robot obstacle avoidance strategy and path planning technology is one of the key technology for.
3.2 Multi-sensor fusion technology
In order to make the robot vacuum cleaners work, must be on the position of the robot, posture, speed and system state monitoring, and robotic perception the working environment of static and dynamic information, the robot cleaner corresponding work order and operation content can be naturally adapt to changes in the work environment, usually divided into internal and external sensor, wherein the internal sensor encoder, linear accelerometer, gyroscope, magnetic compass is used to control and monitor the robot itself; the external sensor includes visual sensors, ultrasonic sensors, infrared sensors, contact and proximity sensor, installed in the robot itself for the sense of purpose external environment information. From the domestic cleaning robot can be seen, the cleaning robot uses a large number of sensors, effectively putting a lot of sensor observation information fusion processing, thus enabling the robot to obtain the most substantial external environment information, its main advantage is in the same observation conditions, can coordinate the use of multiple sensors, the distributions in different positions the more homogeneous or heterogeneous sensor provided by the local incomplete measurements and related database of relevant information to be integrated, elimination of multiple sensor has complex and contradictory, and complementary, to reduce uncertainty, and thus access to the object or environment consistency description, this is a single sensor cannot be obtained. Application of multi-sensor fusion technology to improve the mobile robot, obstacle recognition environment modeling, obstacle avoidance accuracy plays an important role in fusion methods mainly include: the Kalman filtering method, Bayes estimation method, statistical measures, D - s inference method, fuzzy logic method and production rules.
3.3 Vacuum technical
The vacuum cleaner is composed of high-speed rotation of the fan in the body is formed inside a vacuum thereby to produce strong airflow, the dust and dirt suction through the suction machine body of dust filter bag. Vacuum system includes a dust filter, dust bag, exhaust pipes and other accessories, the dust suction capacity depends on the size of the fan speed. Recently, an Australian company developed a new principle of air dust filter. The vacuum cleaner is a closed system, neither the external air suction, and inorganic from gas discharge, so no dust filter, dust bag, an exhaust pipe and other accessories the principle is to use the Coanda effect to form a low pressure gas vortex, the sediment trapped within the vortex chamber of vacuum cleaner.
3.4 Chinese Journal of power sources
Mobile power in cleaning robot plays an important role, it is the source of life of cleaning robot. Mobile power required for moving mechanism with power, control circuit for providing a stable voltage, for vacuum operation module and sensing observation module providing energy. In this field, generally used as mobile power chemical batteries, lead-acid batteries, such as NiCd, NiMi ideal power supply in the discharge process should be able to have: ① to maintain a constant voltage; the small resistance to quickly discharge; ③ rechargeable; the cost is low characteristic. But without a battery may also have these advantages. As a result of indoor mobile robot with small volume, light weight, so the power of the volume weight is also an important consideration, which requires the designer to select a small size, large capacity, can be repeated use of high battery, as much as possible to increase suction machine uninterrupted working time.
4 Conclusion with forecast
Robot vacuum cleaner as a service robot in the field of a new product, will make people in the unattended condition easily complete the indoor environment cleaning work. Therefore, the cleaning robot can mass production to reduce costs, lower prices to enter the market, will have a great market prospect, relevant information is also predicted the cleaning robot is the next few years demand is the largest service robot. Although the country by external cleaning robot research and development has made some achievements, but the cost is too high and many key technical problems to be solved mainly in the following 3 aspects:
(1)at present, the high price is a serious major factors affecting cleaning robots into the home appliance market, in order to significantly reduce the cost, must develop a smart sensor dedicated motion control of digital processing chips; Secondly should see the application of Bluetooth technology in the household appliance industry, through the use of Bluetooth technology to transfer the digital processor of high cost on the user's PC, is expected in the short term to reduce the cost of cleaning robots in thousand Yuan.
(2) future of sucking dust robot will to independent type and artificial intelligent of development, so must combination existing of based on since adaptation control, and forecast control, and fuzzy logic, and neural network, mobile robot movement planning and control technology, research on environment obstacles with does security reliable of anti-collision function of intelligent movement planning and controller and the efficient of sensor fusion algorithm, is in reality environment in the implementation has good of since adaptability and robustness behavior of robot of key.
(3) power supply technology is one of the core problems of cleaning robots work, in addition to robot movement outside, dust control and power circuits, also need to optimize automatic charging, charge to ensure the robot can keep up to date with auto-complete cleaning tasks for the specified environment. Study of improving life expectancy, reducing the volume of chemical batteries at the same time, a new proton exchange membrane fuel cell with big power, high energy, long life and small advantages, provided a suitable power supply for mobile power, at present, the Shanghai fuel cell research at a University in this area is a good attempt. As the key technology of cleaning robots and price-performance continues to improve, or improve, believed on the basis of existing software and hardware conditions, will be launched within the next few years affordable automated cleaning robots, which in turn can make cleaning robots just like regular appliances go into millions of households, for this market and high-tech products bring considerable economic benefits.
