Small values of kₐ make the iterative solver ill-conditioned. This
change reverts to the constant-acceleration feedforward in that case. It
gives _very_ bad results (hence why we added the iterative solver in the
first place), but it's better than hanging.
```
TEST(ArmFeedforwardTest, CalculateIllConditioned) {
constexpr auto Ks = 0.5_V;
constexpr auto Kv = 20_V / 1_rad_per_s;
constexpr auto Ka = 1e-2_V / 1_rad_per_s_sq;
constexpr auto Kg = 0_V;
frc::ArmFeedforward armFF{Ks, Kg, Kv, Ka};
// Calculate(currentAngle, currentVelocity, nextAngle, dt)
CalculateAndSimulate(armFF, 0_rad, 0_rad_per_s, 2_rad_per_s, 20_ms);
}
```
This produces 1 V and doesn't accelerate the system at all. Using
nextVelocity instead of currentVelocity in the feedforward outputs 41 V
and still only accelerates to 0.4 rad/s of the requested 2 rad/s.
I picked the kₐ cutoff by increasing kₐ until the iterative solver
started converging.
Fixes#7743.
The Raspberry Pi 5 is fast enough that we no longer need it.
```
Running ./build/DAREBench
Run on (4 X 2400 MHz CPU s)
CPU Caches:
L1 Data 64 KiB (x4)
L1 Instruction 64 KiB (x4)
L2 Unified 512 KiB (x4)
L3 Unified 2048 KiB (x1)
Load Average: 0.47, 0.72, 0.45
***WARNING*** CPU scaling is enabled, the benchmark real time measurements may be noisy and will incur extra overhead.
-------------------------------------------------------------------------------
Benchmark Time CPU Iterations
-------------------------------------------------------------------------------
DARE_WPIMath_Dynamic 34.4 us 34.4 us 20315
DARE_WPIMath_NoPrecondChecks_Dynamic 21.7 us 21.7 us 32266
DARE_WPIMath_Static 15.2 us 15.2 us 45878
DARE_WPIMath_NoPrecondChecks_Static 7.84 us 7.84 us 89316
DARE_SLICOT 79.4 us 79.4 us 8789
DARE_Drake 34.9 us 34.9 us 20074
```
The Google C++ protobuf implementation has issues with dynamic linkage across DLL boundaries because it uses global variables. It also has a compile-time dependency because the protoc version must exactly match the libprotobuf version. Using nanopb with a customized generator fixes both of these issues.
Co-authored-by: Gold856 <117957790+Gold856@users.noreply.github.com>
Reverts #6609 since that fix didn't Just Work(tm) on Windows. (edit: or Ubuntu. Seems to have broken everything except macOS.) This PR configures CMake to try and find protobuf-config.cmake first, which allows protobuf to pull in abseil for us. If protobuf-config.cmake is not available (coprocessors which don't have a new enough protobuf installed are a common case), it will fallback to CMake's built-in FindProtobuf module, which is what we were using before.
Add wpi::CreateMessage, a wrapper with an ifdef to switch between Arena::CreateMessage and Arena::Create, since the former is deprecated in newer versions of protobuf. This allows forward compatibility with newer versions of protobuf.
LTVUnicycleController is a drop-in replacement with better tuning knobs.
The RamseteCommand examples were removed instead of retrofitted with
LTVUnicycleController because we're planning on removing the command
controller classes anyway, so it would be wasted effort. The
SimpleDifferentialDriveSimulation example shows direct
LTVUnicycleController usage.
This implements de/serialization for the types that aren't templated (SwerveDriveKinematics) in C++ or where there is no trivial way to go round-trip (Splines) for the messages.
Made JNI modifications to expose the faster function, made the API use
the typesafe Matrix API, and synchronized the documentation with C++.
Sped up C++ LTV diff drive test from 20 ms to 15 ms.
Sped up C++ LTV unicycle test from 15 ms to 10 ms.
15 m/s is about 50 ft/s, which is way above what FRC robots should be
able to achieve. This limit lets us catch user errors from bad unit
conversions immediately instead of the LUT generation in the LTV
controllers hanging for a really long time.
Fixes#5027.
This is enabled by the C++20 __VA_OPT__ feature.
Uses of "{}" format string were updated.
Some warning suppressions were required for older clang versions.
Also improve codegen of wpi::Logger::Log(), frc::ReportError(), and frc::MakeError();
these generate better and less redundant code if they use fmt::string_view for the
format string instead of templating on it.
Now, implicit narrowing conversions are only used with wpi::Now(). This
also fixes clang-tidy warnings about C-style casts. For example:
```
== clang-tidy /__w/allwpilib/allwpilib/wpilibNewCommands/src/main/native/include/frc2/command/SwerveControllerCommand.inc ==
/__w/allwpilib/allwpilib/wpilibNewCommands/src/main/native/include/frc2/command/SwerveControllerCommand.inc:95:18: warning: C-style casts are discouraged; use static_cast/const_cast/reinterpret_cast [google-readability-casting]
auto curTime = units::second_t(m_timer.Get());
^
```
In that case at least, the cast was removed entirely since Get() already
returns a units::second_t.
