SYSTEM AND METHOD FOR MORE EFFICIENT AUTOMATIC IRRIGATION BASED ON A LARGE NUMBER OF CHEAP HUMIDITY SENSORS AND AUTOMATIC FAUCETS

摘要

The most efficient water irrigation systems today for gardens and/or fields typically use dripping systems that release drops of water at certain distance intervals for example for about 30-60 minutes per day (for example every 30-100 cm of the pipe there is dropper that releases typically 2 litters of water per hour) and are typically controlled by timers that start or stop the water in the main pipes. However, although this is in general more efficient than systems that do not use droppers, this can still be far from optimal since it does not take into account different needs for each area, depending for example on the individual needs of each plant, heterogeneity of soil type, different amount of Sun or shade in each part of the garden or field, different number of plants in each area, etc. In other words, irrigation systems based on pipes with droppers, typically controlled only with a timer, which are the most common form of irrigation used today, suffer from one very basic weakness, which is that they have no feedback, so they are in essence working blindly. On the other hand, normal humidity sensors and automatic faucets are expensive, and also many of the known methods for humidity sensing suffer from various limitations, such as for example limited range of response, sensitivity to changes in the salinity of the ground, sensitivity to changes in temperature of the ground, etc. The present invention tries to solve the above problems by providing much cheaper humidity sensors that are still quite reliable and also much cheaper automatic faucets, so that preferably each plant or (preferably small) group of plants can be automatically watered by an individual set of moisture sensor and automatic faucet. The attainment of cheap automatic faucets is preferably done by using at the end nodes of the system low water pressure, so that much less force is needed to open and close the local waterway, and then either using much simpler electrical valves that do not require engines, or circumventing the need for electrical valves altogether, by using mechanical sensors that control a mechanical valve or directly exert pressure on a flexible pipe, as explained below. Another possible variation, instead of mechanical sensors and valves, is to use some chemical control that takes advantage of the behavioral tendency of the water itself, such as for example using a preferably synthetic material that tends to behave like a normal root preferably at the edge of each side channel, so that the "root" counter-balances the water supply and reaches equilibrium with it when the soil becomes wet enough, based preferably on asymmetric capillary materials.