Difference between revisions of "Future Autopilots"

Latest revision as of 03:53, 25 January 2013

Proposed additions

We're always looking for great ideas. If you'd like to see something added or changed on Tiny v2.11 list it here! Please keep your suggestions relevant to this revision and post other requests in the Hardware Wish List.

Separate GPS Option

see TWOG/v1.0

EMI filters on ADC channels

On Semiconductor NUF4220MNT1G 4-line EMI Filter

Analog sensors are severely affected by video and modem RF. We typically see ADC reading fluctuations of +/-0.5% in a well shielded installation, but a misbehaving video transmitter or a noisy Radiotronix modem can affect ADC channels by more than 50% in the same well shielded installation. The addition of effective filters to the ADC inputs should greatly reduce the effects of RFI and allow for a much broader range of RF equipment and airframe configurations.

I suggest the On Semiconductor NUF4220MNT1G. A 2mm x 2mm chip that filters 4 analog signals, attenuatiing RF frequencies above 16 Mhz but particularly the 800 Mhz to 5 Ghz range. (Jeremy)

NUF4220MN is a 4 line LC EMI filter array designed for audio applications. It offers greater than -30 dB attenuation at frequencies from 800 MHz to 5.0 GHz, with no line loss. This part is a single chip solution for audio interface applications, 2 speaker lines with a microphone line. This device also offers ESD protection-clamping transients from static discharges and ESD protection is provided across all capacitors.

Decoupling capacitor on GPS antenna
The u-blox reference design calls for a 47pF 10% 0603 capacitor in series between the receiver and antenna. I have no idea why this is useful but apparently it must be, because this technique is commonly seen on WiFi cards, video transmitters, modems, even R/C receivers. Maybe we're missing out on something great? (Jeremy)

This is typically used as a DC block capacitor. Many RF amplifier circuits either require DC on their output to be powered, or have stray DC on the output. Also, many antennas are shorted at DC. The capacitor serves as a high-pass filter that allows minimal loss at RF frequencies. It isn't necessary unless the manufacturer specifies it.(hpux735)

Filtering for GPS antenna

Make some sort of low pass or band pass filter to reject outside frequency's. This would be useful since most UAV's are not just used to fly but for video or other sorts of communication which tend to interfere with the GPS Signal. Maybe similar to some of these designs http://www.webx.dk/rc/video-wireless/filtergps.htm (Danstah)

Re: I have since found out that the lea-4p has a built in saw tooth filter. Adding a filter would probably only reduce the signal strength

VIRTUAL AUTOPILOT (The Next Logical Step)*

The virtual autopilot concept is based on virtualizing the autopilot through the Paparazzi GCS software and meant for larger aerial platforms. The avionics unit will be an actual micro pc running Linux such as http://www.fit-pc.com/web/ or the gumstick. The altimeter, gyro, servos, sensors, cameras, custom I/O , etc... are all modular. The telemetry/datalink is a remote desktop connection to the pc on the remoted vehicle (remote vehicle has a hardware in the loop type configuration).

The modular design saves autopilot hardware development costs. The modular design also saves repair costs. For example, currently if sensors and other components become infused with the autopilot board and the board or sensor goes bad repair costs raises. A modular design with a virtualized autopilot creates an environment for rapid development and integration of anxilary equipment (sensors etc...). Hecto's Paparazzi software suite is perfectly designed for virtualizing an autopilot because its meant for autopilot development (I must add its ahead of its time!).

Think of all the hardware you can run through usb ports alone and all the programs you can run simultaneously on a pc. With a remote desktop connection through a TM link, your UAV increases its functionality significantly. Akira Devereaux http://akiraproject.net/cv

@@ Line 1: / Line 1: @@
-== Tiny 2.1 is almost done! ==
+{| align=right
-[[Image:tiny11vs20.gif|thumb|Eagle screencap comparing the current Tiny 1.1 to the new 2.0 version]]The complete re-reouting of the Tiny autopilot was done on October 9, 2007.  The new design is not a bug-fix as no known flaws exist with the current 0.99 and 1.1 versions, so the redesign is performance, easy to use and easy to assemble-oriented!
+|-
-=== Feature additions ===
+|<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Autopilots</categorytree>
+|}
-* Hardware flow control on the modem
+== Proposed additions ==
-: The LPC has one "full-featured" serial port and one basic serial port.  Previous versions had the full-featured port hard-wired to the GPS in order to leave the basic port open for initial bootloader programming.  Tiny 2.1 exchange these ports and use the GPS Reset signal to "disconnect" the GPS for the one-time bootloader programming.
+We're always looking for great ideas.  If you'd like to see something added or changed on ''Tiny v2.11'' list it here!  Please keep your suggestions relevant to ''this revision'' and post other requests in the [[Hardware_Wish_List|Hardware Wish List]].
-* TI PTH08080WAH switching 5V/2.25A regulator
+* Separate GPS Option
-: This integrated power supply module greatly simplify manufacturing, reduce costs, and improve performance.  Tiny 2.1 have a voltage input range of 6-16V and enough 5V power for large servos and high-power modems and video systems.
+: see [[TWOG/v1.0]]
-* 3.3V/1A linear regulator in a SOT223 standard pinout package.
+* EMI filters on ADC channels [[Image:EMI_Filter_NUF4220.gif|thumb|On Semiconductor NUF4220MNT1G 4-line EMI Filter]]
-:The new Tiny uses a 1A LDO linear regulator which is capable of providing plenty of power to modems or other devices but tests have shown that any device with irregular power consumption can cause significant voltage fluctuations on the critical 3.3V bus.  Users are advised to use a separate regulator as needed for such devices.  The new regulator will have at least 200mA available for peripherals to be used with caution.
+: Analog sensors are severely affected by video and modem RF.  We typically see ADC reading fluctuations of +/-0.5% in a well shielded installation, but a misbehaving video transmitter or a noisy Radiotronix modem can affect ADC channels by more than 50% in the same well shielded installation.  The addition of effective filters to the ADC inputs should greatly reduce the effects of RFI and allow for a much broader range of RF equipment and airframe configurations.
+:I suggest the [http://www.onsemi.com/PowerSolutions/product.do?id=NUF4220MNT1G On Semiconductor NUF4220MNT1G].  A 2mm x 2mm chip that filters 4 analog signals, attenuatiing RF frequencies above 16 Mhz but particularly the 800 Mhz to 5 Ghz range. [[User:Jeremy|(Jeremy)]]
+:<small>NUF4220MN is a 4 line LC EMI filter array designed for audio applications. It offers greater than -30 dB attenuation at frequencies from 800 MHz to 5.0 GHz, with no line loss. This part is a single chip solution for audio interface applications, 2 speaker lines with a microphone line. This device also offers ESD protection-clamping transients from static discharges and ESD protection is provided across all capacitors. </small>
-* Video/payload power switch.
+* Decoupling capacitor on GPS antenna
-:The TPS1100 transistor used on the previous Tiny design has proven extremely useful but is intended for high-speed power switching of motor controllers and occupies a 5mm x 6mm space (SOIC-8).  The replacement is a Ultra Low On-Resistance MosFet (165mOhms/2.6A) in small SOT23 package.
+*: The u-blox reference design calls for a 47pF 10% 0603 capacitor in series between the receiver and antenna.  I have no idea why this is useful but apparently it must be, because this technique is commonly seen on WiFi cards, video transmitters, modems, even R/C receivers.  Maybe we're missing out on something great? [[User:Jeremy|(Jeremy)]]
+This is typically used as a DC block capacitor.  Many RF amplifier circuits either require DC on their output to be powered, or have stray DC on the output.  Also, many antennas are shorted at DC.  The capacitor serves as a high-pass filter that allows minimal loss at RF frequencies.  It isn't necessary unless the manufacturer specifies it.[[User:hpux735|(hpux735)]]
-* Larger GPS ground plane and antenna
-: The 13mm antenna on previous Tiny 1.1 proved to be an unworthy exchange of performance for weight. Crude parking-lot tests showed an approximate 3dBi loss (as expected from the data sheets), but the narrow bandwidth of the small antenna made it more sensitive to de-tuning from nearby components in the aircraft.  Flight performance was acceptable but poor climb rate calculations were observed with the smaller antenna.  Tiny 1.1 users are advised to fit a 20mm antenna.
-:Tiny 2.1 use a 20mm x 4mm or 18mm x 4mm antenna and feature 30% more ground plane area.
-* GPS Reset connected to a GPIO pin on the MCU
+* Filtering for GPS antenna
-:Occasionally the GPS fails to boot properly, displays very poor S/N ratios, and fails to obtain a valid fix. This may be caused by a slow power-up of the 5V or 3V regulators, or by some unusual EMI that is only present at boot. Usually a simple power cycle will correct the problem but occasionally the receiver seems to use the backup battery to retain the bad state. This feature allow the operator to reset the GPS as needed.
+: Make some sort of low pass or band pass filter to reject outside frequency's. This would be useful since most UAV's are not just used to fly but for video or other sorts of communication which tend to interfere with the GPS Signal. Maybe similar to some of these designs http://www.webx.dk/rc/video-wireless/filtergps.htm [[User:Danstah|(Danstah)]]
+Re:
+I have since found out that the lea-4p has a built in saw tooth filter. Adding a filter would probably only reduce the signal strength
-* Connector changes
-: Tiny 2.1 feature revised header layouts on all peripherals.  The modem header have CTS/RTS/DTR and both 5V and 3.3V supplies (3.3V is shared with LPC and ADC channels - use with caution and only with very low power modems like the 10mW Xbee).
-: The button is removed and it's function is combined on the USB header along with an LED trigger so that indicator, button, and USB can be remotely mounted.
-: New separate headers with their own supply :
-::* Vertical Infrared (1 ADC) with 3.3v supply
-::* Horizontal Infrared (2 ADC) with 3.3v supply
-::* 2 general purpose ADC with both 3.3v and 5v supplies
-::* 2 general purpose ADC with optional on-board  5v -> 3.3v resistor bridge and both 3.3v & 5v supplies
-::* Two axis Camera control with two servo signal, vdo switch control, vdo power switch and both 5V and 3V supplies
-::* SPI bus with 3.3V supply
-::* I2C bus with both 5V and 3V supplies
-* 3 LEDs with attached test point
+* VIRTUAL AUTOPILOT (The Next Logical Step)*
-* 0603 components
+The virtual autopilot concept is based on virtualizing the autopilot through the Paparazzi GCS software and meant for larger aerial platforms. The avionics unit will be an actual micro pc running Linux such as http://www.fit-pc.com/web/ or the gumstick. The altimeter, gyro, servos, sensors, cameras, custom I/O , etc... are all modular. The telemetry/datalink is a remote desktop connection to the pc on the remoted vehicle (remote vehicle has a hardware in the loop type configuration).
-: Many users don't really think that using 0402 components is a great saving from any viewpoint. Even if one saves a little space by using these components, there must still be enough room around to solder it by hand with a soldering iron. With the Tiny 2.1, the assembly will be a bit more friendly to everyone, not only to the beginners.
+The modular design saves autopilot hardware development costs. The modular design also saves repair costs. For example, currently if sensors and other components become infused with the autopilot board and the board or sensor goes bad repair costs raises. A modular design with a virtualized autopilot creates an environment for rapid development and integration of anxilary equipment (sensors etc...). Hecto's Paparazzi software suite is perfectly designed for virtualizing an autopilot because its meant for autopilot development (I must add its ahead of its time!).
-=== Proposed additions ===
+Think of all the hardware you can run through usb ports alone and all the programs you can run simultaneously on a pc. With a remote desktop connection through a TM link, your UAV increases its functionality significantly.
-We're always looking for great ideas.  If you'd like to see something added or changed on ''Tiny 2.1'' list it here!  Please keep your suggestions relevant to ''this revision'' and post other requests in the [[Hardware_Wish_List|Hardware Wish List]].
+''
+Akira Devereaux'' http://akiraproject.net/cv
-* Separate GPS Option
+[[Category:Autopilots]]
-: To provide more flexible airframe installation, EMI trouble resolution, and GPS hardware optimization, a second version of Tiny 2.1 will be created with no GPS receiver or antenna.
-: (the only problem is to find a name for this new autopilot [[User:Michel|(Michel)]] :)
-* EMI filters on ADC channels [[Image:EMI_Filter_NUF4220.gif|thumb|On Semiconductor NUF4220MNT1G 4-line EMI Filter]]
-: Analog sensors are severely affected by video and modem RF.  We typically see ADC reading fluctuations of +/-0.5% in a well shielded installation, but a misbehaving video transmitter or a noisy Radiotronix modem can affect ADC channels by more than 50% in the same well shielded installation.  The addition of effective filters to the ADC inputs should greatly reduce the effects of RFI and allow for a much broader range of RF equipment and airframe configurations.
-:I suggest the [http://www.onsemi.com/PowerSolutions/product.do?id=NUF4220MNT1G On Semiconductor NUF4220MNT1G].  A 2mm x 2mm chip that filters 4 analog signals, attenuatiing RF frequencies above 16 Mhz but particularly the 800 Mhz to 5 Ghz range. [[User:Jeremy|(Jeremy)]]
-:<small>NUF4220MN is a 4 line LC EMI filter array designed for audio applications. It offers greater than -30 dB attenuation at frequencies from 800 MHz to 5.0 GHz, with no line loss. This part is a single chip solution for audio interface applications, 2 speaker lines with a microphone line. This device also offers ESD protection-clamping transients from static discharges and ESD protection is provided across all capacitors. </small>
-* Decoupling capacitor on GPS antenna
-*: The u-blox reference design calls for a 47pF 10% 0603 capacitor in series between the receiver and antenna.  I have no idea why this is useful but apparently it must be, because this technique is commonly seen on WiFi cards, video transmitters, modems, even R/C receivers.  Maybe we're missing out on something great? [[User:Jeremy|(Jeremy)]]
-* Power plug
-*: Most users agree that the 1.25mm Molex is inadequate for the 8-16V / 1-2A main power input.  The obsolete ''Lite'' board used a 4-pin 1.25mm molex to address this issue but it was akward to connect two pairs of tiny 26AWG wire to the large main-power wires.  ''Tiny 0.9'' used a "Futaba/Hitec" style header for battery input - the idea was that you could simply modify your ESC moving the 5V wire over to the battery input terminal.  This solution occupied a lot of space on the Tiny and the modified ESC could easily end up mistakenly connected to standard r/c equipment.  Tiny 2.1 is currently slated to have large solder pads on the input capacitors that users can solder their own wires to.  Please post suggestions for a "better" method, if one exists.

Difference between revisions of "Future Autopilots"

Latest revision as of 03:53, 25 January 2013

Proposed additions

Navigation menu

Search