robotic system for
surveys and environmental analysis
The Rover is designed to explore open spaces and or closed for environmental surveys
The surveys to be analyzed can be of Gaseous as Methane, Gpl, Alchool, Hydrogen.
Controlling the temperature of the atmosphere and soil, humidity, atmospheric pressure, air quality control, and Particulate Matter.
The rover is equipped with GPS coordinates for geographical card IMU 9 degrees of freedom that integrates an accelerometer, a magnetometer, a gyroscope to calculate the position of the rover that will compare with the GPS data.
For the location of obstacles, Right, Left, Forward, Behind and Dislivelli excessive traction Rover are managed by Ultrasonic Sensors.
The Rover is driven by 6 gearmotor planetary model P205.24.25 of micromotors.
Noise suppression engine with VDR.
Output shaft supported by two ball bearings.
Maximum radial load: 300N (10 mm from the mounting flange).
Maximum axle load: 150N.
Direction of rotation depending on polarity.
It can be mounted in any position.
Operating temperature: -20 ° C / 60 ° C
Approximate Weight: 700 / 900g
and 'possible to apply an encoder.
The 6 are piloted 3 Controller Dual MC33926 Motor Driver Carrier.
This dual brushed DC motor driver, based on
Freescale’s MC33926 full H-Bridge,
has a wide operating range of 5 – 28 V and
can deliver almost 3 A continuously (5 A peak) to each of its two
motor channels. The MC33926 works with 3 – 5 V logic levels, supports
ultrasonic (up to 20 kHz) PWM, and features current feedback, under-voltage protection,
over-current protection, and over-temperature protection.
The dual MC33926 motor driver carrier is a breakout board featuring two Freescale MC33926 H-bridge ICs. It can supply up to almost 3 A continuous current per channel to two brushed DC motors at 5 – 28 V, and it can tolerate peak currents up to 5 A per channel for a few seconds, making this a great general-purpose motor driver for medium-sized DC motors and for differential-drive robots that use such motors. The MC33926 supports ultrasonic (up to 20 kHz) pulse width modulation (PWM) of the motor output voltage, which eliminates the audible switching sounds caused by PWM speed control, and a current feedback circuit for each motor outputs an analog voltage on its respective FB pin that is proportional to the output current. Since this board is a carrier for the Freescale Semiconductor MC33926 H-bridge.
In a typical application, five I/O lines are used to connect each motor
driver channel to a microcontroller: the two input lines, IN1 and IN2, for
direction control, one of the disable lines, D1 or D2, for PWM speed
control, the current sense output, FB, for monitoring motor current draw
(connected to an analog-to-digital converter input) and the status flag, SF, for monitoring motor driver
errors. The control lines can be reduced to two pins per channel if PWM signals
are applied directly to the two input pins with both disable pins held
inactive. In each of these cases, the other unused lines must be set to enable
For example, if D2 is used for the PWM input (as is
typically the case), D1 must be held low to prevent it from disabling the motor
driver. The circuit board provides convenient jumper points for overriding the
motor driver defaults without having to connect extra wires to the module.
The current sense and status flag connections are optional, though
monitoring of the status flags can allow detection of latched fault conditions.
The status flags are open-drain output, so the two status flag can be wired
together for applications where I/O pins are scarce and determining which motor
driver is experiencing a fault condition is not necessary.
Note that the default state of the enable pin, EN, is LOW, which holds
both motor driver chips in a low-current sleep mode. You will need to hold this
pin high (either with an external connection or via the default-overriding
jumper next to the pin) to allow the board to run.
The MC33926 has under-voltage, over-current, and over-temperature
protection. Some protection events are indicated by the status flag pins (SF), which are active-low pins that can be connected connected to a single
input. If the chip detects an over-current or over-termperature event, the SF is
latched LOW and OUT1 and OUT2 are set to high-impedance. To unlatch the status flag pin toggle the D1, D2 ,
EN or VIN lines. The carrier board has a reverse-protection MOSFET for added
protection to the motor driver chips.
The MC33926 motor driver used on this carrier board has a maximum
current rating of 5 A continuous. However, the chip by itself will
overheat at lower currents. For example, in our tests at room temperature with no forced air flow,
the chip was able to deliver 5 A for 5 s and 4 A for 18 s
before the chip’s thermal protection started reducing the current. A continuous
current of 3 A was right at the over-temperature threshold; in some tests the thermal protection kicked in after a minute, and in
other tests the chip delivered 3 A for over five minutes without
triggering thermal protection. The actual current you can deliver will depend
on how well you can keep the motor driver cool. The carrier’s printed circuit
board is designed to draw heat out of the motor driver chips, but performance can be improved by adding a heat sink. Our tests were
conducted at 100% duty cycle; PWMing the motor will introduce additional
heating proportional to the frequency.
The management controller is managed by a tiny
but powerful card the μNAV.
In practice the μNAV is a board only 43x43 mm
can control two motors with encoder adjusting, very efficiently, the speed,
measure the distance covered, running a trapezoidal acceleration /
deceleration, run a command set that It enables various types of movement in a
totally automated, eg advance of the tot centimeters at a precise speed and
Among the various functions is also provided the
possibility to connect up to four μNAV in cascade, it acts as a master the
others are slaves, in order to control the robot up to four axes (eight
wheels), all the calculations for the speed of the wheels are done locally,
this can greatly simplify the management of robots four- and six-wheel drive.
For the rover they will use 3 cascade.
The batteries that feed it are two 12V 26Ah Lead to manage the mechanical and logic II level, while the second 12V 10Ah Lead solely to manage the PC Board (the Heart of the Rover).
A Test completed, will be replaced with 2
Batteries LifePO4 12V 22Ah
10Ah Balancer 2Ah 12V LiFePO4 being connected in
series for 24V, and a third LTE LiFePO4 12V 22Ah for the alone
The series LTE and 'a family of batteries at 12V
in direct replacement of lead-acid batteries are compatible with most of the
alternators of the vehicles on the market.
Compatible with chargers for lead-acid batteries
offer the best performance with a specific charger for lithium iron phosphate.
Effective both as storage batteries / services that as starter batteries Used where 'request superior light weight and durability and above capacity' of delivering linearly entire capacity 'also rated on heavy loads are available in different sizes and suitable for use in series or parallel.
Rapid recharging in 1 hour charger with adequate
Like all lithium batteries without the control
electronics must be protected from excessive discharges above 10 volts.
-small electrical tools agricultural.
-camperistica and leisure.
-apparati electronic self.
-groups of continuity.
Nominal voltage 12 V Operating voltage under load is 12.0 V.
Capacity 22 AH +/- 5%.
Operating voltage max 14.8V - min 11.5V At 80% DOD, > 1500 cycles.
Deep discharge voltage 11 V The cells is damaged if voltage drops bellow
Maximal charge voltage 15V (or 16 V) The cells is damaged if voltage
exceeds this level.
Optimal discharge current < 10 A 0.5 C.
Maximal discharge current < 60 A 3 C, continuous for max 15 minutes from full charge.
Max peak discharge current < 200 A 10 C, maximal 5 seconds in 1
Max peak discharge current < 260 A maximal 3 seconds in 1 minute
Optimal charge current < 10 A 0.5 C
Maximal charge current < 20 A < 1 C with battery temperature monitoring
Maximal continuous operating
80 °C The battery temperature should not increase this level
during charge and discharge
Dimensions 181 x 167 x 77 Millimeters (tolerance +/- 2 mm)
Weight 3.4 kg Kilograms (tolerance +/- 150g).
In addition, the Rover is also equipped with a GSM system where this may 'send any kind of SMS message or receive SMS messages, where this may' acquired by a series of strings, commands for a recovery of the same or to a malfunction of the Wifi because too far or shielded.
The Rover once received the coordinates of where to go for relief, will be autonomous to seek a shorter path and / or resolve any obstacles along the way.
Once there, the Rover will base and propel its Robotic Arm Linear,
where gear is T.P.U. (Head tools-holder).
The head is in the shape of a hexagon and not by chance, because on a base of 140 mm x 2
there will be a puncher, an aspirator, a gripper, sensors like a thermometer
for measuring the ground temperature, a humidity sensor / liquid soil, a laser pointing, a Mini Dolly Cam that follows the tool that you are using at the time is that it can 'also be used independently.
The logical part and divided into several parts.
Logic Level II, managed by one or more microcontrollers that will run: Sensors, Controllers Motors, lights, Robotic Arm, GSM, IMU.
The microcontroller (if I can aim) can talk to each other through a bus Rs485.
While the logic of the level will be managed by a Board Intel PCs on the Windows platform, the hardware that will be connected to and controlled GPS, A Wifi Router for Telemetry and connections for the management of USB microcontrollers.
In addition all the data managed by the PC-Board will be saved in a database, for this not to have active always sending data via Wifi.
The Rover once made the necessary surveys and received the command of the return, return to the starting point that the base, of course, following a map that will store back point by point until you get to the point of destination.
All data from the survey will be sent via telemetry, and samples will be taken from Rover in special containers.
The structure of the rover was initially designed with lightweight material such as aluminum, but then it is folded on an iron frame for convenience of welds and for future expansion.
The profile is rectangular with measures 50x30 2mm thick tempered.
They will be mounted on the frame 6 Dampers F / F 40x30 to dampen vibrations or shocks between the frame and the box of electronic equipment.
The suspension system is a rocker-bogie in case of REV2e very simple but effective.
The Rover can turn on itself in two ways, typical of track that is three wheels in one direction and the other in the other direction very consuming energy, or bending the two wheels in front and two behind inward thanks 4 Actuators 50mm.
The cam mounted on the main box and a retractable room, in the movements of the Rover Cam is set in the retracted position to avoid camera shake and vibration, while retaining all the functions of pan / tilt, when the rover is stopped, the Cam can be extended outside of the box to 18cm.
Air Quality Monitoring
Support for micromotors P205 Encoder
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