Essay: What kind of sensor can we use for certain parameters.

First of all, the sensors which we’re going to use, need to be waterproof. The communication between the vehicle and the computer will be underwater. This can be realized by using beacons.
For communication, we can use a ultrasonic sensor which is waterproof and cost around $11,- and has the following specifications:
Electrical properties:
‘ Electrical parameters: JSN-SR04T
‘ Operating voltage: DC 5V
‘ Quiescent current: 5mA
‘ Total current work: 30mA
‘ Acoustic emission frequency: 40khz
‘ Farthest distance: 4.5m
‘ Blind: 25cm
‘ Wiring: + 5V (positive power supply)
‘ Trig (control side) RX
‘ Echo (the receiver) TX
‘ GND (negative)
‘ Module size: 41mm * 28.5mm
‘ Resolution: about 0.5cm
‘ Angle: less than 50 degrees
‘ Working temperature: -10 ~ 70 ‘
‘ Storage temperature: -20 ~ 80 ‘
Product Features:
1. small size, easy to use;
2. low voltage, low power consumption;
3. high accuracy;
4. strong anti-jamming;
5. integrated waterproof probe, suitable for wet & harsh measurement occasions.
‘
Can be used for:
1. Horizontal distance;
2. Obstacle avoidance, automatic control;
3. The object approaches, there is a perceived
4. Traffic control;
5. Security, industrial control;
6. Artificial intelligence, and research
The basic working principle:
‘ using IO port TRIG trigger location, to the high level signal of at least 10us (nano seconds);
‘ module automatically sends 8 40KHz, automatic detecting whether a signal return;
‘ a signal return, a high level is output through the IO port ECHO, the time duration of the high level is ultrasonic from launch to return.
The test distance = (high level time * speed of sound (340M/S)) /2
‘
Which sensors are useful to measure depth
MBP180:
The BMP180 is a barometric pressure sensor with an I2C (‘Wire’) interface.
Barometric pressure sensors can measure the absolute pressure of the air around them. This varies with both the weather and altitude. You can monitor changes in the weather, measure altitude, or any other tasks that require an accurate pressure reading, depending on how you interpret the data.
Underwater GPS:
A Dutch researcher has developed a system to be able to do underwater positioning. Normal GPS does not work under water, nor is it necessary system to indicate the time. The system of the Dutch-operates with a mesh network of nodes.
Wouter Kleunen soon PhD at the University of Twente, the concept of “underwater GPS”, which works with a kind of mesh network and individual nodes. Because these nodes can exchange data, information about location and timing, a more precise localization is enabled for under water use than with current systems.
The mesh network makes contact through acoustic signals, because that appears to be the best way of communication underwater. W. Kleunen has not tested the whole system yet. However, he has made experiments with portions of the system.
W. Kleunen had to create his own mac protocol for his system, because existing MAC protocols would not work with the transfer of location and time information, but only with other data.
The mesh networks will not form a worldwide working system, such as GPS is. However, there are already some projects to deploy the system into practice. “The environments are difficult, testing is difficult and therefore the adoption will be slow,” W. Kleunen.
Also W. kleunen is not planning to make a business of it. “There are no patents on my work and as far as I know, the methodologies and algorithms are free to use. The software and hardware designs that are protected and that will be something to be done in the future, in the form of a company, but concrete plans are not there yet. It’s an academic project. “