Design overview: Difference between revisions

From Rsewiki
(Created page with "==Design overview hardware== File:blockdiagram_rev2.png Hardware blockdiagram. Most blocks are off-the-shelf hardware modules from PJRC (Teensy), Pololu (motor, driver a...")
 
No edit summary
 
(40 intermediate revisions by the same user not shown)
Line 1: Line 1:
==Design overview hardware==


[[File:blockdiagram_rev2.png]]
Back to [[regbot | Regbot]] main page.


Hardware blockdiagram.
==Design overview hardware==
Most blocks are off-the-shelf hardware modules from PJRC (Teensy), Pololu (motor, driver and buck-boost converter) and Sparkfun (IMU).


A line sensor is planned, but not implemented yet.
Regbot consist of a microprocessor board (teensy 3.2/3.5) that controls 2 motors (Pololu 25D) through a motor driver (MC33926). Motor rotation data is collected from motor encoders. Motor current is avaiable and there is further a gyro-accelerometer sensor (see figure 1 below).  


==Design overview software==
The processor is supplied with 5V from either USB or from a 12V battery or power supply.


[[File:blockdiagram_software.png|900px]]
A start button that starts a mission and a power button that enables power after a shutdown.


Overview of software data flow. Yellow is control blocks.
The robot is differential controlled, where a difference in velocity between left and right wheel generates a turn.
Green is hardware (motor and sensors), Light green is calculations. Light blue is obtained values.
Gray is input values.


Sample time for all controllers and data values are 1ms.
The processor is an ARM MK20DX256 processoren (a 32bit 96MHz microprocessor) and is programmed to implement a number of control loops that is able to control some basic movements of the robot (see figure 2).
All software is written in c++, based on Arduino libraries.




* [[Design calculations]]
[[File:regbot_hardware-blocks.png|600px]]


==PCB connections revision 2B==
Figure 1. Hardware blockdiagram.
Most blocks are off-the-shelf hardware modules from PJRC (Teensy), Pololu (motor, driver and buck converter) and Sparkfun 9150 (IMU). Some of the supported sensors are optional, but all will have gyro to enable balancing and most also wifi to enable monitoring and confuguration without a USB cable.


Component placement and values (in red) are shown here.
Other sensors like an line (edge) detector (edge of a tape line on the floor), IR distance sensors (Sharp 2Y0A21 type) and wifi access may be implemented on some of the robots.
Plug connections are shown in blue.


[[File:component-drawing.png]]
==Design block diagram==


The Sharp IR sensor output is not connected to an AD converter input.
The robot data and control flow is shown as a block diagram in figure 2 below.


The IR sensor voltage divider output should be between 0 and 1.2V,
[[File:blockdiagram_software.png|700px]]
and could be connected to A0 and A1 (used to be feedback from motor-controller).
Unfortunately a plug can not be mounted (space conflict with USB plug).


The orange wires are patches (line sensor low power at pin 32 and from IR sensor to A0 and A1).
Figure 2. Overview of software data flow. Yellow is control blocks.
Green is hardware (motor and sensors), Light green is calculations. Light blue is obtained values.
Gray is input values from mission.


==Install hardware - version 1A==
Sample time for all controllers and data values are 1ms.
All software is written in c++, based on Arduino libraries.


The motor and IMU wires are mounted as shown here.
All controllers can be switched off. I.e. if the velocity controller is switched off then the motors will never run. To control the motor voltage (rather than the velocity) then configure the velocity controller vith Kp = 0 and feed forward Kf=1.
The IMU uses 4 wires only, so only the rightmost pins (1..4) on the main board are used.


[[File:motor-imu-wire.png]]
* [[Design calculations]]
 
Pin 1 on the IMU is as shown here
 
[[File:imu-wire.png]]
 
The teensy processor and power is connected as shown
 
[[File:teensy-annotated.png]]

Latest revision as of 14:39, 11 January 2021

Back to Regbot main page.

Design overview hardware

Regbot consist of a microprocessor board (teensy 3.2/3.5) that controls 2 motors (Pololu 25D) through a motor driver (MC33926). Motor rotation data is collected from motor encoders. Motor current is avaiable and there is further a gyro-accelerometer sensor (see figure 1 below).

The processor is supplied with 5V from either USB or from a 12V battery or power supply.

A start button that starts a mission and a power button that enables power after a shutdown.

The robot is differential controlled, where a difference in velocity between left and right wheel generates a turn.

The processor is an ARM MK20DX256 processoren (a 32bit 96MHz microprocessor) and is programmed to implement a number of control loops that is able to control some basic movements of the robot (see figure 2).


Figure 1. Hardware blockdiagram. Most blocks are off-the-shelf hardware modules from PJRC (Teensy), Pololu (motor, driver and buck converter) and Sparkfun 9150 (IMU). Some of the supported sensors are optional, but all will have gyro to enable balancing and most also wifi to enable monitoring and confuguration without a USB cable.

Other sensors like an line (edge) detector (edge of a tape line on the floor), IR distance sensors (Sharp 2Y0A21 type) and wifi access may be implemented on some of the robots.

Design block diagram

The robot data and control flow is shown as a block diagram in figure 2 below.

Figure 2. Overview of software data flow. Yellow is control blocks. Green is hardware (motor and sensors), Light green is calculations. Light blue is obtained values. Gray is input values from mission.

Sample time for all controllers and data values are 1ms. All software is written in c++, based on Arduino libraries.

All controllers can be switched off. I.e. if the velocity controller is switched off then the motors will never run. To control the motor voltage (rather than the velocity) then configure the velocity controller vith Kp = 0 and feed forward Kf=1.