1. ROSLab: A High-level Programming Environment for Robotic Co-design
Nicola Bezzo, Peter Gebhard, Andrew King, Junkil Park, Oleg Sokolsky, Insup Lee

2. ELECTRONICS SYNTHESIS
Objective
1) Development of a Simplified High-Level Programming Language for Robotic Applications.
2) Complete Robot Synthesis.
HL code generation
LL code generation
Hardware description generation
PRINTABLE QUADROTOR
ELECTRONICS SYNTHESIS
Y. Mulgaonkar, V. Kumar (UPenn)
PRINTABLE INSECT
M. Piccoli, M. Yim (UPenn)
A. Mehta, M. Tolley, D. Rus (MIT)
A. Mehta, M. Tolley, D. Rus (MIT)

3. Graphical Block - ROS Code Pairing
#include <messages/encoder.h>
void encoderCallback (const messages::encoder_msg::ConstPtr& enc_message) {
EncoderVelC = “operation involving number of ticks read by encoder” }
ros::Subscriber enc_sub;
enc_sub = node.subscribe ("/encoder_topic", 1, encoderCallback); =
ENCODER
/encoder_topic
EncoderVelC

4. How does ROSLab generate code?
Formal Code Generation to C++ / ROS
data structure and semantic check
port type check
Template with “holes”
$includes$
$pub_ports$
$sub_port_values$
$sub_port_callbacks$
int main(int argc, char **argv) { //----MAIN
ros::init(argc, argv, $node name$);
ros::NodeHandle node;
$pub_connections$
$sub_callback_setup$
ros::Rate r(100);
while(ros::ok()) { //----WHILE
ros::spinOnce();
// ***** ADD YOUR CODE HERE *****
// *********************************
r.sleep();
} // --- end while
return EXIT_SUCCESS;
} // --- end main
Advertise Example
$port_name$ = node.advertise<$port_type$> ("$port_topic$", 1);
port_name
port_topic
port_type

5. ROSLab Demo

6. SCHEDULING OF CONTROLLERS
TF = 2 sec
1 Hz
1 Hz
SENSOR 1
CONTROLLER 1
CruiseControl VX WZ
SENSOR 2
Controller 2
Obstacle Avoid.
Controller 3
Waypoint Nav
2 Hz
- Fixed delay

7. SCHEDULING OF CONTROLLERS
TF = 3 sec
1 Hz
1 Hz
SENSOR 1
CONTROLLER 1
CruiseControl VX
1 Hz P
2 Hz
2 Hz
SENSOR 2
Controller 2
Obstacle Avoid. WZ
2 Hz
Controller 3
Waypoint Nav
- Planner to decide which controller is active/inactive

8. TIME CONSTRAINT
Freshness constraint: bounds the time it takes for data to flow through the system
F(Y|X)=10 Y delivered at time t, then X-value to compute Y is sampled no earlier than t-10 ms
Separation constraint: constraints the jitter between consecutive values on a single output channel
l(Y)=3  Y delivered at a minimum rate of 3ms
u(Y)=13  Y delivered at a maximum rate of 13ms

9. Control System SchedulingA θ θS v τ
RATE
TS = ?
TC = ?
TA = ?
freshness / separation
freshness: F(τ|θ) = f(θs(t-1))
separation: S(τ) = g(θs(t-1))
STABILITY PROPERTIES

10. High-level Software Low-level Software Mechanical Hardware Electronics
SPECIFICATION:
-flight time
-payload
-speed ….
High-level Software
Low-level Software
Specification (flight time, speed, mission time, etc) affect the dimension of the robot, type of motors, type of microcontroller, sensors, and software design.
To build and use a robot we need hardware/mechanical specifications, electronics specification, and low level (microcontroller) and high level (ROS) software programming.
Mechanical Hardware
Electronics

11. Robot Codesign – ROSLab Architecture
HL-SW
SUPERVISOR
Joystick
CONTROLLER 1
Vicon
SWITCH
QUADROTOR
CONTROLLER 2
SENSOR 1
TRPY
Supervisor monitors different controllers and decides which one should be on/off at each time.
Example:
Controller 1 (manual teleoperation) subscribes to joystick messages and translates them into throttle-roll-pitch-yaw commands
Controller 2 gets vicon messages and sends TRPY commands.
Controller 2 actuates when the quadrotor is near obstacles to avoid collisions
CONTROLLER 3
SENSOR N

12. HL-SW LL-SW Electronics ROS NODE Switch TRPY CONTROLLER TRPY
POSE ESTIMATE
PWM
PWM
PWM
PWM
Accel/Ang Vel M1 M2 M3 M4
RADIO
Low level software and electronics on the quadrotor. LL controller will be uploaded on a microcontroller. Microcontroller receives TRPY information through a radio and sends PWM commands to motors. μC
IMU
Electronics

13. Electronics Mechanical M1 M2 M3 M4 RADIO μC IMU LINK LINK BODY LINK
At the hardware level the microcontroller, radio, imu, and other electronics will have to fit within the body of the robot. The body will have certain dimensions to fit the electronics. The motors dimensions and specification (torque, rpms) will affect the size of the entire quadrotor.
LINK
LINK
BODY
LINK
LINK
Mechanical

14. ROSLab – Mechanical Design

15. ROSLab – Electronics Design
RADIO μC
L0 - ROSLab
R.S1 μC.S1 1 1 R S1 μC
PA.0.S1.1/S2/S3
L1 – Service/Pins 2 2 S2
PA.1.S2/S3/S4 3 3 S3
PB.0.S1/S2/S3
L2 – Assignment
Greedy Algorithm
R.S1.1 μC.S1.1/S2/S3.AF0.PA.0
L3 – Low Level μC and Hardware Specification
*.h
*.xml

16. Conclusion ROSLab to generate a complete description of a robot.
MIT Printable Segway and Penn Quadrotor as reference testbed to demonstrate the complete co-design
Scheduling and Real-time analysis
Prove Properties
Time execution: e.g., response time analysis
Information flow: e.g., output depends only on inputs
Simulation tool: e.g., power draw given HW setup
First release available at: