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Empire: Four Kingdoms – Help, my Soldiers are Deserting!

 − at 21:25, 31. Oct. 2014

Help, my Soldiers are Deserting!

Sometimes… it happens.  Your soldiers desert.  It has nothing to do with your personality.  Nothing to do with Unions or pay checks.  It’s more simple than that.

Food.  Yup.  Food… it’s that simple.  or is it?

 

 

Empire Four Kingdoms - Deserting SoldiersYour soldiers need food.  Each soldier has a food consumption.  For example, Macemen consume 2 food per hour.

So 100 Macemen means 200 food is consumed per hour.  If you are not producing more than 200 food per hour, your food goes into the negative… and if your food levels hit zero.  Your troops desert.

And then you have to start over again, building up your army.

So, always keep your food in the positive!  It keeps your troops happy… and everyone knows… happy troops means happy player.  :)

The post Empire: Four Kingdoms – Help, my Soldiers are Deserting! appeared first on Brick Labs.

[original entry]

Video Friday: Beams for Sale, Drone on a Leash, and Open Source Humanoid

 − at 14:28, 31. Oct. 2014



Now's your chance to try out a Beam, if you live in Palo Alto. Or even if not

[original entry]

Baseball Season Over? No Worries, You Can Watch Startup Pitchers Do Battle

 − at 12:00, 31. Oct. 2014



Startup competitions have been Silicon Valley sport for years; now they’re going global

[original entry]

Robots: Nylon Fishing Line Actuator

 − at 08:00, 31. Oct. 2014

In this episode, Ron Vanderkley speaks with Professor Geoffrey Spink from Wollogong University about his team's work on artificial muscles. Professor Spink's Australian led team are able to produce artificial muscles from nylon fishing line that can contract by about 50% of their original length, can generate forces that are over 100 times larger than our own muscle, and produce a mechanical power output of over five kilowatts per kilogram - similar to a jet engine. He tells us that “the advantage of using something as simple as fishing line or sewing thread is that they're really cheap and they're readily available... The tools we need to make the fishing line muscles are fishing line, a hair dryer, and an electric drill.”

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Chinese Drivers Welcome Our New Robocar Overlords

 − at 17:00, 30. Oct. 2014



A new poll shows China and India more favorable to self-driving cars than Japan and the West

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The Defibrillator Drone Is Another Good Drone Idea But Will It Work?

 − at 16:40, 30. Oct. 2014



Medical emergency drones are a fantastic idea, but that doesn't mean that we're going to get them

[original entry]

Intel Video Featuring the HR-OS1

 − at 16:27, 30. Oct. 2014

intel video HR-os1

Check out this Intel video featuring the HR-OS1 Humanoid Endoskeleton and our Own Andrew Alter. Andrew talks about the different things that the HR-OS1 can do and how its designed to interact with the world.

[original entry]

Harman Cancels Out Road Noise, Without Headphones

 − at 15:00, 30. Oct. 2014



Autos can now cancel noise from the engine and the road; what's next, the kids in the back seat?

[original entry]

How to Make a UAV – Lesson 1: Terminology

 − at 19:19, 29. Oct. 2014

How to Make a UAV – Lesson 1: Terminology
How to Make a UAV – Lesson 2: The Platform
How to Make a UAV – Lesson 3: Choosing the right motor / prop / ESC / Battery
How to Make a UAV – Lesson 4: Choose a flight controller
How to Make a UAV – Lesson 5: Assembly*
How to Make a UAV – Lesson 6: Get it all working together
How to Make a UAV – Lesson 7: FPV & Long-range

So you’re looking to get into drones and UAVs? This tutorial series is designed to help you understand the emerging field of UAVs and guide you through the process of building your own UAV using off-the shelf parts. The terminology and definitions used here are intended to give you, the reader an understanding of each term rather than a dictionary definition. Although many words may have multiple meanings, the definition is used in the context of UAVs / Drones.

Terminology

Types

ARF Almost Ready to Fly“: a UAV which comes assembled with almost all parts necessary to fly. Components like the controller and receiver may not be included.
BNF Bind and Fly“; the UAV comes fully assembled and includes a receiver. You only need to choose a compatible transmitter and “bind” it to the receiver.
DIY Do It Yourself“, which is now commonly used to mean “custom”. This normally involves using parts from a variety of different suppliers and creating or modifying parts.
Drone This is synonymous with UAV. The term “drone” seems to be more common for military use whereas “UAV” is more common for hobby use
Hexacopter
A UAV which has six motors / propellers.
Multirotor “Multirotor” simply means an aircraft with multiple rotors
Octocopter A UAV which has eight motors / propellers.
Quadcopter A UAV which has four motors / propellers and four support arms. Configurations are normally “+” (the front of the UAV faces one of the arms) or “X” (the front of the aircraft faces between two arms).
RTF Ready To Fly“: a UAV which comes fully assembled with all necessary parts. Simply charge the battery and fly!
Size (mm) “Size” is normally provided in millimeters (ex 450mm) and represents the greatest point to point distance between two motors on a UAV. Size can also determine the “class” of UAV (micro, mini etc)
Spyder A “Spyder” type UAV (normally quad or hex) is one where the supporting arms are not symmetric in bot haxes when looked at from the top.
Tricopter A UAV which has three motors / propellers, and usually three support arms
UAV Unmanned Aerial Vehicle” (of any kind)
V-Tail A UAV which has four arms, of which the rear two are at an angle to form a ‘V’
X4 / X8  X4 and X8 are UAV configurations with four support arms; X4 configurations have one motor at the end of each arm, whereas X8 have two motors per arm (one facing up, the other facing down)
Y3 / Y6 Y3 and Y6 are UAV configurations with three support arms; Y3 configurations have one motor at the end of each arm, whereas Y6 have two motors per arm (one facing up, the other facing down)

Quadcopter

Quadcopter

V-Tail

V-Tail

Octocopter

Octocopter Frame

Mechanics

CG Center of Gravity“; this is the point on the aircraft where there is equal weight distributed on all sides.
Clamp A “tube clamp” is a device normally used on a round tube in order to connect it to another device (such as a motor mount or a UAV’s body).
Connectors In order to plug and unplug wires, connectors are used at the ends of wires. Common connectors for batteries are Deans & XT60, while connectors for the flight controller and sensors are 0.1″ spaced
Dampeners These are molded rubber parts used to minimize vibration transmitted throughout a UAV
Frame The frame is like the “skeleton” of the aircraft and holds all of the parts together. Simple frames have motors connected to aluminum or other lightweight extrusions (“arm”) which then connect to a central body.
G10 This is a material commonly used instead of carbon fiber to make a UAV’s frame since it is very rigid and lightweight, but significantly less expensive
Landing Gear
Multirotor landing gear normally does not have wheels as you might find on an airplane – this is to prevent it from moving when on the ground and reduce overall weight.
LED Light Emitting Diode“. These are used to make the UAV visible, primarily at night or low lighting conditions.
Prop Guards “Propeller guards” are material which curround a propeller to prevent the propeller from contacting other objects. They are implemented as a safety feature and a way to minimize damage to the UAV
Retract “Retractable” normally refers to landing gear which has two positions: one for landing and takeoff, and another, which takes up less room or improves visibility, during flight.
Shell This is an aesthetic / functional cover used to improve resistance to the elements and sometimes improve aerodynamics. Some production UAVs only have a plastic shell which also acts as the “frame”.

Dampener

Anti-Vibration Dampener

Landing Gear

Simple Landing Gear

UAV Shell

UAV Shell

 

Propulsion

BEC Battery Eliminator Circuit“: a voltage regulator built into the ESC which can provide regulated 5V DC power to any electronics which need it.
Blades Propeller blades are the aerodynamic surface which generates lift. A propeller normally has two to four blades which can be fixed or folding.
CW / CCW CW indicates Clockwise rotation and CCW indicates Counter-Clockwise rotation. On a multi-rotor aircraft, you would normally use pairs of counter-rotating propellers.
ESC Electronic Speed Controller” is the device which connects to the battery, motor and flight controller and controls the speed at which the motor rotates
LiPo Lithium Polymer” is the most common battery used in drones and UAVs because of its light weight (versus storage capacity) and high current discharge rates.
There are other types of Lithium-based batteries available on the market as well (LiFe, LiMn, LiOn etc)
Motor The motor is what is used to rotate the propellers; in small UAVs, a brushed motor is most often used, whereas for larger UAVs, a “brushless” motor is much more common
PCB A “Printed Circuit Board” is the flat fiberglass part with many components soldered to it. Many electronic products have a PCB.
Power Distribution
In order to power so many different devices used in a UAV, the battery must be split, which is where the Power Distribution (board or cable) comes into play.
It takes the single positive and negative terminals of the battery and provides many different terminals / connection points to which other devices (operating at the same voltage) can receive power.
Propeller The propellers are what provides the thrust and are more similar to those used in airplanes rather than on helicopters.
Prop Adapter A device used to connect the propeller to the motor.
Prop Saver A type of hub which mounts on top of your motor and replaces the prop adapter. In he event of a crash, a part of the prop saver is lost in an attempt to save the propeller.
Servo A servo is a type of actuator which, provided the right signal, can move to a specific angular position
Thrust The “thrust” is the force which a specific motor and propeller can provide (at a certain voltage). Usually measured in kilograms (Kg) or pounds (Lbs)

LiPo Battery

LiPo Battery

Propellers

CW / CCW Propellers

Power Distribution

Power Distribution Board

Control

Base / ground /
Control Station
Instead of (or in addition to) a hand held transmitter, a station (normally in a case or mounted to a tripod) is used to house / integrate the necessary components used to control a UAV.
This can include the transmitter, antenna(e), video receiver, monitor, battery, computer and other devices.
Binding The term “binding” refers to configuring a handheld transmitter so it can communicate with a receiver; if a transmitter came with a receiver, it should have been done at the factory.
Channel The number of channels on a transmitter relates to the number of separate signals it can send
Flight Controller The “Flight Controller” is what would be considered the “brain” of a UAV and handles all of the data processing, calculations and signals.
The core of a flight controller is often a programmable “microcontroller”. The flight controller may have multiple sensors onboard, including an accelerometer, gyroscope, barometer, compass, GPS etc.
If the flight controller has the ability to control the aircraft on its own (for example to navigate to specific GPS coordinates), it may be considered to be an “autopilot”.
Harness This usually refers to the “Wiring Harness” which are the wires that connect the receiver to the flight controller (and sometimes other devices).
HF/ UHF / VHF High Frequency“; “Very High Frequency” and “Ultra High Frequency” radio waves. Units are in Hz (Hertz)
Receiver This is what processes the information received wirelessly
Sketch / Code This is the program which is uploaded to your UAV’s flight controller (similar to a “thought process”)
Transmitter / Radio
The “transmitter” is what generates the control signal(s) wirelessly to the receiver

 

Base Station

Base Station

Transmitter

Transmitter

Flight Controller

Flight Controller

Sensors / Orientation

Accelerometer An accelerometer measures linear acceleration in one to three axes. Units are normally in ‘g’ or gravity. An accelerometer can provide your drone’s orientation with respect to ground
Antenna Antennas are what actually receive or send a signal to and from a UAV (the signal itself having been generated by a transmitter unit).
They come in a variety of different types and include directional (strongest in one direction) and omnidirectional
Barometer / Pressure 
/ Altimeter
A Barometer is used to give feedback as to the altitude of the UAV. It measures pressure, and since pressure changes with altitude, your aircraft can “know” its height.
Compass A magnetic compass can provide your compass heading (north / south / east / west)
Flight Recorder A flight recorder records sensor values from your UAV. This feature can sometimes be integrated into the flight controller.
GPS Global Positioning System“: satellites orbiting the planet send out signals which are picked up by the GPS antenna and are sent to be processed by the GPS receiver to provide geographic coordinates
Gyroscope A gyroscope measures angular acceleration in one ot three axes. Units are normally degrees per second squared.
IMU Inertial Measurement Unit” combines an accerleometer and a gyroscope
Magenetometer In low cost robotics, a magnetometer is sometimes used to provide compass direction
Pitch Pitch is the angle of the nose to tail with respect to the ground, or in other words, the rotation of an aircraft about the axis from wing to wing
Pitot Tube A device which measures air speed
Roll Roll is the rotation of the aircraft along the axis from its nose to its tail
Yaw Yaw is the rotation of an aircraft about an axis perpendicular (90 degrees to) to the plane formed between the nose / tail and wing tips
Roll Pitch Yaw

Roll / Pitch / Yaw

Airspeed Sensor

Airspeed Sensor

GPS

GPS Module

Video

FPV First Person View“: The UAV is mounted with a camera and the operator has a live video feed displayed on either a monitor or virtual reality glasses
Gimbal
A devices which carries a camera and is normally actuated using either a servo motor or a brushless DC motor. A gimbal is what can stabilize a camera in flight.
GoPro The GoPro series of action cameras is widely used for taking and/or transmitting video
LCD Liquid Crystal Display” is a type of screen / monitor used to display the image received by the receiver
OSD On Screen Display” provides text on the monitor / screen which is being sent from the aircraft (can include altitude, GPS location etc.)
VR Virtual Reality” glasses or goggles provide the operator with a more “immersive” experience

Gimbal

2-Axis Gimbal

FPV Monitor

LCD Monitor for FPV

VR Glasses

VR Glasses

Do you Really Want a Custom UAV?

The choice of UAV depends on how much you want to learn about the field. Building a custom UAV can be quite involved as well as dangerous. If you would prefer to simply “get in the air” quickly, we’d suggest the following, in increasing order of complexity:

Toy

Multi-rotor toys are becoming increasingly popular. Most are small, and can fit in the palm of your hand, though some like the A.R. Drone Parrot are larger. Toy multi-rotor UAVs are not necessarily easy to fly, but are more resistant to crashes. Toys tend to be smaller and integrate the frame into the aesthetic shell.

RTF

A “Ready To Fly” kit includes all the parts needed for a complete UAV. Parts include the UAV itself (most often pre-assembled and pre-wired), the hand held transmitter, a battery and charger. The craft is calibrated and should be able to fly with relative ease. These are not however indestructible, and a crash may damage the system to the point where it is simply worth buying a new aircraft rather than attempting to repair it.

ARF

An “almost ready to fly” kit is one where the frame, motors and most of the “core” parts are included and fully assembled (or a few parts need to be assembled, largely to help with shipping). Normally an ARF kit requires the addition of a transmitter / receiver and perhaps batteries and charger. Other ARF kits do not include the flight controller itself. You may need to do some calibration because of the additional parts required. We do not suggest a BNF kit as not all transmitters and receivers are compatible with one another.

UAV Kit

A kit normally includes most of the important products needed to build a UAV, but may not include the transmitter / receiver, battery and charger or flight controller. Different kits have different package contents, so it is important to see exactly what is included and what additional items will be needed. The contents of a kit should be compatible with one another.

Custom

A custom setup is where you combine a variety of different products from a variety of different manufacturers and get them to work together. This approach requires that you understand which components are needed to make a UAV and will be the focus of this series of articles.

 

Do you see terms which are missing and would be useful? Feel free to add them in the comments below.

          

Related Stories

 

[original entry]

New Package: mongodb_store

 − at 19:00, 29. Oct. 2014

From Nick Hawes via ros-users@

I would like to announce the release of a new suite of tools to enable the persistent storage, analysis and retrieval of ROS messages in a MongoDB database.

The mongodb_store package:

http://wiki.ros.org/mongodb_store

... provides nodes to store arbitrary ROS messages in a MongoDB database, query the database and retrieve messages, with helper classes in C++ and Python. Nodes are also available to provide rosbag-like functionality using the [same db format] (http://wiki.ros.org/mongodbstore#LoggingofTopics:mongodblog) and also [parameter persistence across system runs] (http://wiki.ros.org/mongodbstore#Parameterpersistence:config_manager.py).

Packages are available on Ubuntu for Indigo and Hydro, e.g.

  • ros-indigo-mongodb-log - The mongodb_log package
  • ros-indigo-mongodb-store - A package to support MongoDB-based storage and analysis for data from a ROS system, eg. saved messages, configurations etc
  • ros-indigo-mongodb-store-msgs - The mongodbstoremsgs package

These tools were developed by the STRANDS project to support the development, debugging and runtime introspection of long-term autonomous mobile robots, but we hope they will be useful to the ROS community more generally.

In the near future we plan to release tools for serving maps from mongodb_store and for logging streams of RGB-D data in a compressed format .

Note that there is an overlap in functionality between these tools and warehouse-ros. We developed our own solution as the existing packages appeared to be unsupported and special-purpose, but as this appears to be changing, we may want to look at combining these two packages.

For feedback, pull requests, feature requests and bug reports please go to: https://github.com/strands-project/mongodb_store/issues

[original entry]