## 3 Information and Communication Technology Solutions for Precision Agriculture
### Multi-Purpose Platforms
#### 3.4.2 Cyber-Physical Systems  
CPSs were also treated as multi-purpose platforms in this paper, since they often utilize various technologies around data collection/analysis/storage/sharing, AI, IoT, etc. Some prominent CPS solutions can be used for measuring soil properties as well as for applying variable rates of fertilizers and pesticides based on the crops' spatial and/or temporal variability. [PERSON] et al. demonstrate the use of a UAV-based automatic pesticide distribution system, which reduces the exposure of farmers to dangerous chemicals and optimizes the use of water and pesticides. The aforementioned system captures photos of the crops and analyzes the images to identify which areas require the use of pesticides. Based on the results of this analysis as well as on geolocation data from a global positioning system (GPS), it automatically distributes the proper amount of pesticides to each area using a pulse width modulation (PWM) controller, which regulates the flow of the pesticide through a sprinkler [90]. [PERSON] et al. demonstrate a novel robotic variable rate fertilization system which is capable of achieving precise fertilization application rates according to the soil requirements. This system can be controlled remotely using a smartphone application. It uses GPS data for its navigation and utilizes an actuator for the proper dosing of the fertilizer. Reduced costs as well as reduced environmental pollution and resource waste were some of the most important benefits of the proposed system [91]. [PERSON] et al. demonstrate a robotic platform which measures several soil properties by means of penetration measurements. The specific platform automatically detects obstacles which could potentially damage the measurement probes. Navigation can be performed either autonomously via satellite positioning or via remote control [92]. By facilitating phenotyping techniques, CPSs can provide useful information for PA. The term phenotyping refers to the comprehensive assessment of a plant's anatomy and physiology as well as of its complex ontogenetical and biochemical traits. Through phenotyping, useful knowledge can be acquired regarding a plant's growth, yield, stress, etc. [93; 94] [PERSON] et al. present a low-cost, robust, and high-throughput phenotyping robot. Able to capture images from multiple perspectives within plant rows, this system overcomes certain problems (limited coverage area due to capturing from a single perspective, inability to collect all the required phenotypic data, etc.) faced by other similar robotic solutions. Using trait-extraction techniques, significant information regarding the stem width and the plant height can be obtained. A real-time kinematic global positioning system (RTKGPS) is used for the precise navigation of the robotic system. Field testing of the system above indicated high throughput phenotyping capabilities in energy sorghum crops [95]. CPSs can also facilitate various time-consuming agricultural activities (e.g., tilling, seeding, transplanting, harvesting, weed control). [PERSON] et al. analyze the use of a robot for performing unmanned rotary tilling, utilizing a navigation system for obtaining its position and direction. These researchers also propose a double-vehicle operation in which the operator manually operates a conventional tractor while also supervising the operation of a nearby tilling robot. The results estimated 1.8 times increased efficiency as compared to the manned-only operation [96]. [PERSON] et al. demonstrate an IoT-based seed sowing robot which can be controlled through a mobile application. Several components of the proposed system can be fabricated in the house using 3D printing technologies. Important benefits for the farmers regarding the reduction of labor and total costs were also spotted [97]. [PERSON] et al. demonstrate a rice transplanting robot using the RTKGPS and data from various sensors for its navigation. The specific system was found to have satisfactory transplanting accuracy.