Beeworks B32 Bedienungsanleitung
!
!
B32 GIMBAL CONTROLLER
USER GUIDE
!
!
!
!
!
!
!
BeeWorks LLC
www.beeworksgear.com
!
Last Modified: April 2014
Based on the “SimpleBGC Software User Manual” by BaseCam Electronics
Copyright © 2014 BeeWorks LLC. All rights reserved.
!
!
!
CHAPTER 1
OVERVIEW
This manual covers the setup, calibration, and operating modes of the BeeWorks B32
Gimbal Controller + IMU. It also covers the “SimpleBGC GUI” software application
produced by BaseCam Electronics.
The basic principle of the B32 Gimbal Controller is to input data from a stand-alone inertial
measurement unit (IMU) to control three brushless motors, each of which is responsible
for stabilizing an axis. The IMU contains electronic accelerometers and gyroscopes to sense
roll, pitch (tilt), and yaw (pan). If using the B32 Gimbal Controller to stabilize a camera,
the IMU must be mounted in the same location as the camera to sense camera movement.
PEDIGREE
The B32 Gimbal Controller is a circuit board manufactured in the USA by BeeWorks under
license to BaseCam Electronics. The BeeWorks B32 Gimbal Controller is manufactured in a
facility designed for the production of aerospace electronics and meets all standards set
forth in the Restriction of Hazardous Substances (RoHS) Directive.
The reference design from BaseCam Electronics is named “SimpleBGC” (Brushless Gimbal
Controller). Different manufacturers, such as BeeWorks, have licensed and adapted this
design into their own products. This manual covers the BeeWorks version of the 32-bit
SimpleBGC. Since the design is based on a standard architecture, most of the material in
this manual applies to other versions of the board, as well.
BaseCam Electronics also develops a multi-platform software application called SimpleBGC
GUI (Graphical User Interface), which is used to configure their gimbal controller family.
This manual includes material from BaseCam’s “SimpleBGC Software User Manual” that
BeeWorks has edited and adapted for this guide.!
!2
!
!
!
CHAPTER 2
GETTING STARTED
We recommend that you test your B32 Gimbal Controller, motors, and IMU before
installing them in your application. For this test, you will need to accomplish the following
steps, all of which are described in greater detail later in the manual but outlined here
1. Download and install the SimpleBGC GUI software application from BaseCam
Electronics: www.basecamelectronics.com/downloads/32bit/
2. Connect the B32 Gimbal Controller to your computer with a mini USB cable. If your
computer does not detect the controller automatically, you can download the latest
drivers from the following link: www.silabs.com/products/mcu/pages/
usbtouartbridgevcpdrivers.aspx
3. Connect the IMU and motors to the B32 Gimbal Controller. Reference Figure 2.1 below
for proper connections.
4. Auto-detect the number of poles for your motors or enter the number manually. For
more information, refer to the NUM.POLES description.
5. Set parameters P=0, I=0.1, D=0 for each axis. For more information, refer to the PID
description.
6. Connect your battery to the B32 Gimbal Controller. The B32 Gimbal Controller comes
with a power cable that has bare wire leads. Solder a connector to the wires that mates
with the connector on your battery. Pay careful attention to the positive and negative
terminals on your battery and ensure that you never short them or connect the battery
backwards. Doing so will damage the B32 Gimbal Controller and may cause your battery
to explode. Make sure that your battery is between 8 and 25V.
"3
Note: If you are using a Lithium Polymer (LiPo) battery, this voltage spec means you need between a
3S and 6S battery. The “S” designation is the number of cells, and each cell is 3.7V. Therefore, a 3S
LiPo is 11.1V, while a 6S battery is 22.2V.
7. Set enough POWER to get the motors to move.
8. Test the full system by rotating the IMU sensor board around each of its three axes.
Make sure each motor is moving when you do so. Motors should spin smoothly when
you move the sensor. A small amount of jitter is normal, due to the magnetic force
between rotors and stators known as “cogging” effect.!
"4
Figure 2.1 B32 Gimbal Controller Connectors
!
!
!
CHAPTER 3
STEP-BY-STEP SETUP
The following section outlines the steps required to set up and tune a gimbal using the B32
Gimbal Controller. Refer to later sections of this manual for greater details about the
software settings. This section is intended to provide a “big picture” view of the overall
process, so that you understand the purpose of more detailed sections in the manual. The
steps below assume you have completed a basic setup test, as specified in Chapter 2:
Getting Started.
STEP #1:
CONNECT THE B32 GIMBAL CONTROLLER TO YOUR COMPUTER
Connect the board to your computer with a mini USB cable. The first time you connect the
board to your computer, it may install the drivers automatically. If not, you can download
the latest drivers from the following link: www.silabs.com/products/mcu/pages/
usbtouartbridgevcpdrivers.aspx
After you install the driver, a new virtual COM port will be created. You need to choose this
COM port in the SimpleBGC GUI software application to initiate the connection.
Caution: It is safe to connect both USB and the battery simultaneously, but be very careful not to reverse
the polarity of the battery, because it will burn out the controller and may damage your PC!
!
"5
STEP #2:
UPDATE THE FIRMWARE
Your BeeWorks B32 Gimbal Controller comes preloaded with the latest firmware at the
time it is shipped. You can verify that you have the latest firmware by connecting the board
to a computer with a mini USB cable. This connection also will enable you to adjust
settings on the board itself.
STEP #3:
ADJUST GIMBAL MECHANICS
Mount the camera on the camera tray and balance the gimbal in all three axes. Stabilization
quality depends on balance quality. To check the balance, ensure the gimbal is turned off,
hold the gimbal in your hands and make fast motions along all three axes. If the camera
remains still, then the gimbal is balanced correctly. Proper balance and low friction will
reduce power consumption and improve stabilization quality.
If you rewound the motors yourself, we recommend checking the winding. Remove the
motors from the gimbal, connect them to the controller and set parameters P=0, I=0.1,
D=0 for each axis. Set enough POWER to get the motor to move, and connect your battery.
Motors should spin smoothly when you move the sensor. A small amount of jitter is normal
due to the magnetic force between rotors and stators (“cogging” effect).
Pay great attention to the IMU sensor installation. The IMU axes must be parallel to the
motor axes, and the IMU must be configured properly (i.e. mounting orientation set). Pay
close attention to mechanical linkages. They must be extremely rigid and backlash-free. The
IMU sensor provides feedback data for stabilization, and small amounts of freedom or
flexibility will cause feedback delays and low-frequency resonances. In such cases, it will be
more challenging to find acceptable PID settings and ultimately will result in unstable
performance in real-world conditions (multi-rotor frame vibrations, wind, etc).
STEP #4:
CALIBRATE THE SENSOR
CALIBRATING THE GYROS
Each time you turn the controller on, it takes about 7 seconds to power-up and calibrate the
gyro. Try to immobilize the sensor (camera platform) as much as possible in the first few
seconds after power-up, while the green LED is blinking.
"6
If you activated the option to “Skip gyro calibration at startup,” the gyro is not calibrated
every time, and the controller will start working immediately after power-up. Recalibrate
the gyro manually if you notice degradation in the stabilization quality.
CALIBRATING THE ACCELEROMETERS
It is necessary to calibrate the IMU prior to installation, and it is recommended to re-
calibrate it occasionally, particularly when the temperature changes significantly.
Simple calibration mode – Set the IMU sensor flat on the table and press CALIB.ACC in the
software (or the menu button on the controller, if it is assigned). The LED will blink for 3
seconds. Do not move the sensor during calibration. The sensor does not need to be
connected to the camera platform for this step, as you are calibrating the sensor, not the
camera.
Advanced calibration mode – Perform calibration in simple mode first, as described above.
Then, rotate the sensor board so that each side of the sensor faces up (6 positions total).
Fix the sensor in each position, press the CALIB.ACC button in the software and wait about
3-4 seconds while the LED is flashing. The order of the other sides does not matter, as long
as the base position used in the Simple calibration mode is first. You do not need to press
the WRITE button —calibration data is written automatically after each step.
NOTE: Precise accelerometer calibration is extremely important for holding the horizon during dynamic
movements or yaw rotation.
STEP #5:
TUNE BASIC SETTINGS
Prior to tuning the gimbal, ensure that the IMU is configured and calibrated and that Follow
Mode is not enabled (ensure “Estimate frame angles from motors” is offand Follow YAW is
off). “+” should be set to zero. PWM frequency should be set correctly for your application
prior to tuning.
1. Connect the battery.
2. Set POWER such that the motors have enough torque to hold the camera in place but
do not overheat. Wait at least five minutes to ensure the motors do not get too hot at
that setting. Find the lowest power setting that still provides adequate holding torque,
even when the camera is disturbed.
3. Set PID values for all axes to zero.
"7
4. Auto-detect the number of poles and the motors’ direction. If you know the number of
poles for your motors, it is best to enter the value manually. Do not proceed to the next
step until proper direction is detected.
5. It is best to configure the PID settings for each axis individually, starting with PITCH. To
check stabilization quality, use the peak indicator (shown by the blue traces and blue
numbers) in the control panel on the right of the software. Incline the frame by small
angles, and try to minimize the peak values by increasing P, I and D according to the
following algorithm:
i. Set “I” to a small value of 0.05 or less.
ii. Slowly increase “P” until the motor starts to oscillate.
iii. Increase “D” in small increments until the oscillations stop.
iv. Repeat steps ii and iii until high-frequency vibration occurs. You may feel the
vibration by hand and see a noisy line on the gyro graph. At this point, you have
identified the maximum values for “P” and “D” for PITCH for your setup. Decrease
each slightly and proceed to step v.
v. Repeat steps i through iv for ROLL. Stabilization of ROLL may cause instability in
PITCH. If so, reduce P and D slightly for PITCH. Cross-axis interference is most
pronounced when the gimbal construction is less rigid.
vi. Repeat steps i through v for YAW.
vii. Increase “I” for PITCH until low-frequency oscillation appears. Then, decrease “I”
slightly to keep the gimbal stable. You can reduce “I” as much as 20%, if needed.
viii. Repeat step vii for ROLL and YAW.
ix. When all axes are tuned, test the gimbal. You may find it helpful to use the gyro
data from the Realtime Data tab to estimate stabilization quality. Turn offall data
except GYRO and gently tap the camera in the direction of the axis you are
configuring. This impulse will display on the graph as a fading wave as shown in
Figure 3.1 below. The oscillation should damp within two to four cycles. If the
oscillation continues beyond that point, further adjustment of the rig is required.
Reduce the gain factors (P, I) or increase the damping factor D to reduce these
oscillations.
The result of good tuning is that stabilization error will be less than one degree when you
gently rock the gimbal’s frame.!
"8
STEP #6:
CONNECT AND CONFIGURE REMOTE CONTROL (RC)
Connecting a RC system to the gimbal is optional. A configuration that includes a RC
system will allow control and aiming of the gimbal independently from the direct physical
movements of the gimbal unit.
1. Connect one of the RC receiver’s free channels to the RC_PITCH input, making certain
to preserve the correct polarity in the RC Settings tab.
2. Set SOURCE=PWM.
3. Assign RC_PITCH input to the PITCH axis.
4. Leave all other axes and CMD as “no input.”
5. For the PITCH axis, set MIN.ANGLE=-90, MAX.ANGLE=90, ANGLE MODE=checked,
LPF=5, SPEED=10 (not used in angle mode).
"9
Figure 3.1 Turning PID in the SimpleBGC software application
6. Connect the battery to the main controller and receiver, and check that RC_PITCH input
receives data in the “Realtime Data” tab (slider should be filled blue and reflect stick
movement).
Now you can control camera PITCH from your RC transmitter from -90 to 90 degrees.
If you are not satisfied with the speed of movement, adjust the “I” setting for PITCH in
the “Basic” tab.
Experiment with SPEED mode to determine if SPEED or ANGLE mode is best for your
application.
7. Connect and tune the ROLL and YAW axes the same way, as required.
STEP #7:
TEST THE GIMBAL IN REAL-WORLD CONDITIONS
If your gimbal is attached to a multi-rotor aircraft, connect the controller to the SimpleBGC
GUI software application and turn on the multi-rotor motors. Check the vibrations on the
camera by using the Realtime Data tab / ACC raw data. Try to decrease the level of
vibrations using soft dampers.
NOTE: Brushless motors provide faster reaction than traditional servos but less torque. Depending on
your installation, it may be difficult for the motors to fight against wind and prop-wash. If you are
developing the multi-rotor aircraft frame yourself, try to avoid this influence by lengthening the motor
arms, tilting the motors away from center, or placing the camera above the props. Also, keep in mind that
deflected airflow, when moving at high speeds, can affect the gimbal.!
"10
Inhaltsverzeichnis
