Adding hall sensor on RC sensorless BLDC motor


From a ebike forum:
This one adding hall sensors to outrunner Turnigy C8085-170 from out side.
https://endless-sphere.com/forums/viewtopic.php?f=30&t=15686
But for big motors, put sensor inside is better.

placing hall sensors between slots:

calculation
http://mitrocketscience.blogspot.com/2011/08/hall-effect-sensor-placement-for.html


Legend:
  • edeg : electrical degrees
  • erot: electrical rotation. 1 erot = 360 edeg
  • mdeg : mechanical degrees
  • mrot: mechanical rotation. 1 mrot = 360 mdeg
  • pp : number of magnet pole pairs . 1 pp = 2 magnets (1 north, 1 south) 
  • s : number of slots (in the stator)


Equation 1:      (360 mdeg / pp) = n mdeg per erot =n mdeg per 360 edeg
 a motor controller that requires 120 edeg hall effect sensor placement. You need to find the number of mdeg per 120 edeg. So you just divide the above equation by 3.
equation 2:     (360 mdeg / 3*pp) = m mdeg per 120 edeg.




For example, my Thunder tiger Heli motor, has 10 mags=5 pole pairs, and 12 slots on stator.
I could use the spacing is 24 degree

But, I think I will start with 120 mdegree placement.

But after a test, I found out that this mounting does not have enough flux




I have tested it with a VESC, with 44E sensors. I have had connector issue, it took my one day to figure out what's wrong.
I also tested with a inrunner one:
The facing of hall sensor has to be like this, to have enough flux.

There are also singal pull high to deal with, in a RC sensored BLDC, the sensors are already pull high internally to 5V,(not sure if the ESC does pull high).
On my VESC(FSESC4.12 from flipsky), the pin on VESC are pull highed at 3.3V.
It still work if you connect a RC sensored BLDC to VESC.


There are possibilities to place hall sensor with some off set, VESC and most e bike ESC has a way to test hall sensors combination, in VESC it called hall sensor table. 
But for a RC sensored ESC, not sure about the sensor table used.

and aline with bEMF:


the code is arranged as sensor A at lowest bit, C at highest bit
this chart explains when you read sensor 101, then A wire should be high, B wire should be low to drive to next step.

I use VESC's function to match my DIY hall sensored RC BLDC to existing RC sensored BLDC.for example:
This is a RC sensored BLDC tested in VESC tool under FOC mode, the hall sensor table shows rotor position with 3 hall sensors positions.001,010,011...etc.(the sequence is hall3 at highest bit, hall1 at lowest bit)


With my DIY hall sensor on a in runner BLDC, I manipulate the orders of hall1~3, and the position of hall sensors, to get similar angles and sequence.









































I have tested a RC 13.5T sensored BLDC with VESC:





Connector could also be a issue: VESC using JST-PH 2.0mm pitch, the RC BLDC use JST-ZH 1.5mm as pitch

留言

張貼留言

這個網誌中的熱門文章

Heltec ESP32+OLED+Lora, hardware testing

圖片
you can easily find some good boards from china, but most of them lack of accurate document... Hrere is an example; https://hackaday.io/project/26991-esp32-board-wifi-lora-32 the board looks good with lora and a 128x64 OLED, but the IIC and reset connection is important, since pin can be muxing easily, so every board could be different. pinMode(16,OUTPUT);  digitalWrite(16, LOW); // set GPIO16 low to reset OLED  delay(50);  digitalWrite(16, HIGH); // while OLED is running, must set GPIO16 to high  and, if needed, edit your Wire.begin() to Wire.begin(4,15); (4 = SDA 15 SCL)  i tested it with the Adafruit SSD1306 and the Acrobotics SSD1306 Librarys  both work.  Display size is 128x64 There are discussions on these boards on TＴＮ as a LORA node..or maybee single ch gateway? Heltec has a git :  https://github.com/Heltec-Aaron-Lee And there is another copy call TTGO https://de.aliexpress.com/item/TTGO-LORA32-868-915-Mhz-SX1276-ESP32-Oled-display-Bluetooth-WIFI
閱讀完整內容

micro SD card for ESP32, on lolin32 with OLED and heltec 32 lora oled

圖片
I have purchased 2 micro SD card holder for my esp project. First I would like to test with heltec esp32 lora oled module. this module uses: sck=05 MISO=19 MOSI=27 SS(lora)=18, then I assigned 21 for sd SS and there is a lib in esp32-arduino, which use SS default at 5 I took the example and use SD.begin(21), but I alway get the error: entry 0x40078a9c Card Mount Failed But I do saw once that it read out the sd card type and volume. Not sure it's the issue of lora sd card swithing, or it just can't work. The other esp32 card I have is an wemos esp32 oled, it did not leave me too much pins, I need to find out how to connect sd to it. But I have wemos D1 mini esp8266 on hand, and connect it as:  * The WeMos Micro SD Shield uses:  * D5, D6, D7, D8, 3V3 and G  *  * The shield uses SPI bus pins:  * D5 = CLK  * D6 = MISO  * D7 = MOSI  * D8 = CS It's not working with the example in the arduino IDE 1.8.5, which marked SD(esp8266), but it w
閱讀完整內容

Install Network Time Protocol(NTP) on BeagleBone with Angstrom linux and set local time zone

Referenced from : http://cwraig.id.au/?p=513 1. Update your Package List opkg update 2. Get the ntp Package opkg install ntp ntpdate Update 2014/07/03 for the latest beaglebone image(2013-06-20) with kernel 3.8.12, after this installation,  system will add to service list, so only need to change time zone 3. Now we need to stop the ntpd service so we can request a manual update /etc/init.d/ntpd stop manual update ntpdate pool.ntp.org type in date, you should see the date is changing to current date and time, but the time zone is not corrected. The time zone info is contained in /etc/localtime , use this to remove it: rm /etc/localtime before link up our time zone, look into /usr/share/zoneinfo folder for your timezone. I did not find taiwan in asia, not plan to use hong_kong, but there is still: /usr/share/zoneinfo/Etc/GMT-8 now we make the link with ln command ln -s /usr/share/zoneinfo/Etc/GMT-8 /etc/localtime now type date again to check, should ha
閱讀完整內容