Provides an implementation of a XRP-specific plugin that sends binary messages over UDP (to account for the less performant hardware on the XRP).
This plugin leverages the work already done for the WebSocket protocol and does a translation to/from JSON/binary.
# Background
Unit safety has always been a problem in WPILib. Any value corresponding to a physical measurement, such as current draw or distance traveled, is represented by a bare number with no unit tied to it; it's up to the programmer to know what units they're working and take care to remember that while working on their robot program. This leads to bugs when programmers accidentally mix units without knowing, or measure something (such as a wheel diameter) in one unit and program using another. `wpiunits` is intended to eliminate that class of bugs.
Another source of friction is the controllers and models in `wpimath` that expect all inputs to be in terms of SI units (meter, kilogram, and so on), while most FRC teams are US-based and most commonly use imperial units. wpimath does a good job of noting unit types in method names and argument names; however, it still relies on users properly converting values (and knowing they even have to do so).
# API
There are really only two core classes in this library: `Unit` and `Measure`. A `Unit` represents some dimension like distance or time. `Unit` is subclassed to define specific dimensions (eg `Distance` and `Time`) and those subclasses are instantiated to defined particular units in those dimensions, such as `Meters` and `Feet` being instances of the `Distance` class.
A `Measure` is a value tied to a particular dimension like distance and knows what unit that value is tied to. `Measure` has two implementations - one immutable and one mutable. The `Measure` interface only defines *read-only* operations; any API working with measurements should use the interface. The default implementation is `ImmutableMeasure`, which only implements those read-only operations and is useful for tracking constants. `MutableMeasure` also adds some methods that will allow for mutation of its internal state; this class is intended for use for things like sensors and controllers that track internal state and don't want to allocate new `Measure` objects every time something like `myEncoder.getDistance()` is called. However, the APIs for those methods should still only expose the read-only `Measure` interface so users can't (without casting or reflection) change the internal values.
A `Units` class provides convenient definitions for most of the commonly used unit types, such as `Meters`, `Feet`, and `Milliseconds`. I recommend static importing these units eg `import static edu.wpi.first.units.Units.Meters`) so they can be used like `Meters.of(1.234)` instead of `Units.Meters.of(1.234)`
# Examples
These examples are admittedly contrived. Users shouldn't be interacting much with measure objects themselves, since wpimath and wpilibj classes will be updated to support working with them; users will often just have to take a `Measure` output from one place (such as an encoder) and feed it as input to something else (such as a PID controller or kinematics model)
```java
// Using raw units
Encoder encoder = ...
int kPulsesPerRev = 2048;
double kWheelDiameterMeters = Units.inchesToMeters(6);
double kGearRatio = 10.86;
// always have to remember this encoder will output in meters!
encoder.setDistancePerPulse(kWheelDiameterMeters * Math.PI / (kGearRatio * kPulsesPerRev));
Command driveDistance(double distance) {
// have to know the distance argument needs to be in meters!
return run(this::driveStraight).until(() -> encoder.getDistance() >= distance);
}
// Oops! This will go 16 feet, not 5!
Command driveFiveFeet = driveDistance(5);
Command driveOneMeter = driveDistance(1);
```
```java
// Using wpiunits
Encoder encoder = ...
int kPulsesPerRev = 2048;
Measure<Distance> kWheelDiameter = Inches.of(6);
double kGearRatio = 10.86;
encoder.setDistancePerPulse(kWheelDiameter.times(Math.PI).divide(kGearRatio * kPulsesPerRev));
Command driveDistance(Measure<Distance> distance) {
// Measure#gte automatically handles unit conversions
return run(this::driveStraight).until(() -> encoder.getDistance().gte(distance));
}
// Users HAVE to be explicit about their units
Command driveFiveFeet = driveDistance(Feet.of(5));
Command driveOneMeter = driveDistance(Meters.of(1));
```
```java
SmartDashboard.putNumber("Temperature (C)", pdp.getTemperature().in(Celsius));
SmartDashboard.putNumber("Temperature (F)", pdp.getTemperature().in(Fahrenheit));
```
```java
var InchSecond = Inch.mult(Second); // new combined unit types can be user-defined
var InchPerSecond = Inch.per(Second);
PIDController<Distance, ElectricPotential> heightController = new PIDController<>(
/* kP */ Volts.of(0.2).per(Inch),
/* kI */ Volts.of(0.002).per(InchSecond),
/* kD */ Volts.of(0.008).per(InchPerSecond)
);
var elevatorTop = Feet.of(4).plus(Inches.of(6.125));
elevatorMotor.setVoltage(heightController.calculate(encoder.getDistance(), elevatorTop));
```
This will make is so we can get the right artifact to the installer, and we can do it automatically and its guaranteed to match what built the artifacts.
This reuses many pieces of the current simulation GUI. The common pieces have
been refactored into the libglass library.
The libglass library is designed to be usable for other standalone data
visualization applications (e.g. viewing data logs).
The name "glass" comes from "glass cockpit", as the application features
several multi-function displays that can be adjusted to display robot
information as needed.
These hide the platform specifics behind a common C++ API. Platforms:
- Windows: DirectX 11 (with 10 backwards compatibility)
- Linux: OpenGL 3
- Mac: Metal
This allows access to HAL-level simulation data via a WebSocket connection.
The server additionally serves local files.
The following environment variables can be used for configuration:
HALSIMWS_USERROOT (server) - local directory to use for file serving for /user/ URIs, defaults to ./sim/user
HALSIMWS_SYSROOT (server) - local directory to use for file serving for all other URIs, defaults to ./sim
HALSIMWS_URI (client or server) - WebSocket URI, defaults to /wpilibws
HALSIMWS_PORT (client or server) - port number, defaults to 8080
HALSIMWS_HOST (client) - host to connect to, defaults to localhost
Co-authored-by: Zhiquan Yeo <zyeo8@bloomberg.net>
Co-authored-by: Peter Johnson <johnson.peter@gmail.com>
Co-authored-by: jpokornyiii <jpokornyiii@gmail.com>
The wpimath library is a new library designed to separate the reusable math functionality
from the common utility library (wpiutil) and the hardware-dependent library (wpilibc/j).
Package names / include file names were NOT changed to minimize breakage. In a future year
it would be good to revamp these for a more uniform user experience and to reduce the risk
of accidental naming conflicts.
While theoretically all of this functionality could be placed into wpiutil, several pieces
of this library (e.g. DARE) are very time-consuming to compile, so it's nice to avoid this
expense for users who only want cscore or ntcore. It also allows for easy future separation
of build tasks vs number of workers on memory-constrained machines.
This moves the following functionality from wpiutil into wpimath:
- Eigen
- ejml
- Drake
- DARE
- wpiutil.math package (Matrix etc)
- units
And the following functionality from wpilibc/j into wpimath:
- Geometry
- Kinematics
- Spline
- Trajectory
- LinearFilter
- MedianFilter
- Feed-forward controllers
This uses Dear Imgui to provide a cross-platform integrated GUI for robot
simulation. The GUI provides fully integrated DS and joystick support so it's
not necessary to run the official DS.
This implements enough of the UDP and TCP protocol used by the FRC
driver station to allow us to talk to either QDriverStation or to the
real Driver Station.
This was inspired by a similar function in Toast by Jaci, and also
uses a lot of the research found in the QDriverStation project.
The models and meshes are not included. We will need
to find an alternate way to reintegrate these and use them.
* Add simulation/gz_msgs back, and build with Gradle.
* Add back in the frc simulation plugins for gazebo.
* Add a new shared library, halsim_gazebo.
This library will become the interface between the
HAL sim layer and gazebo.
* Preserve the first channel number used in created Encoders in the Sim MockData.
This allows us to use the DIO channel number to connect with simulated encoders.
* Have the HAL Simulator set the reverse direction on creation.
This enables a simulator to be aware of the direction.
* Add a drive_motor plugin.
This is a bit of a 'magic' motor, which allows us to build robot
models that drive in a more realistic fashion. It does this
by apply forces directly to the chassis, rather than relying on
the complex motion dynamics of a driven wheel.
This in turn allows the model to reduce wheel friction,
reducing scrub, and allowing for a more natural driving experience.
* Modify halsim to be able to load extension libraries if they are available.
It will read the list of libraries to try from the HALSIM_EXTENSIONS
environment variable. Multiple libraries can be given if separated
by ';' (Windows) or ':' (Unix).
The library must have an 'HALSIM_InitExtension' method that returns >= 0 on success.
The library is expected to use the interface expressed by
hal/src/src/main/native/include/MockData
* Add a simple halsim library that just prints robot values.
This makes a good test bed for cross platform purposes,
and provides the ultimate in light weight simulators.
This initial version only prints PWM values.
* Move examples to allwpilib
* Add checkstyle config to examples project
* Ran wpiformat
* Run checkstyle on examples
* Change maximum line length for examples to 80 chars
This number was chosen based on testing of the number of characters shown by default in Eclipse done by @Kevin-OConnor: 51 chars by default on an E09 @ 1024x600 (which has the welcome window open on the right), 71 with welcome closed, 95 with the right-hand outline pane closed
* Add mavenCentral repository
* Rename subproject & error on deprecated API use
* Remove deprecated API usage
* Revert "Force OpenCV to 3.1.0 (#602)"
This reverts commit 50ed55e8e2.
* Removes Simulation
* Removes old build system
* Removes old gtest
* Adds new gmock and gtest
* Updates to new ni-libraries
* removes MyRobot (to be replaced)
* moves files to new location
* Adds new sim backend and new test executables
* updates .styleguide and .gitignore
* Changes cpp WPILibVersion to a function
MSVC throws an AV with the old version.
* Disables USBCamera on all systems except for linux
* 2018 NI Libraries
* New build system
This does a major cleanup on our gradle files, primarily converting all instances of manual dependency downloading to use the correct configuration-based method, which has the advantage of being both less code and more safe.
To publish the simulation zip, run ./gradlew publish -PmakeSim
Targeting Ubuntu 14.04 and 15.10 for now, with 14.04 being the
currently best supported.
Two scripts have been drafted for installing, for 14.04 and 15.10
It currently publishes to ~/releases/maven/development/simulation
There is a known bug that gz_msgs for 15.10 must be built using
protobuf 2.6, which is not the default on 14.04.
Change-Id: I6cccd601671553d30fd05bbbc79c2b7dc1efbf1d
