gtsam 4.1.1
gtsam
IMUFactor.h
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1
7#pragma once
8
12
13#include <boost/bind/bind.hpp>
14
15namespace gtsam {
16
22template<class POSE>
23class IMUFactor : public NoiseModelFactor2<POSE, POSE> {
24public:
26 typedef IMUFactor<POSE> This;
27
28protected:
29
31 Vector3 accel_, gyro_;
32 double dt_;
33
34public:
35
37 IMUFactor(const Vector3& accel, const Vector3& gyro,
38 double dt, const Key& key1, const Key& key2, const SharedNoiseModel& model)
39 : Base(model, key1, key2), accel_(accel), gyro_(gyro), dt_(dt) {}
40
42 IMUFactor(const Vector6& imu_vector,
43 double dt, const Key& key1, const Key& key2, const SharedNoiseModel& model)
44 : Base(model, key1, key2), accel_(imu_vector.head(3)), gyro_(imu_vector.tail(3)), dt_(dt) {}
45
46 ~IMUFactor() override {}
47
49 gtsam::NonlinearFactor::shared_ptr clone() const override {
50 return boost::static_pointer_cast<gtsam::NonlinearFactor>(
51 gtsam::NonlinearFactor::shared_ptr(new This(*this))); }
52
54 bool equals(const NonlinearFactor& e, double tol = 1e-9) const override {
55 const This* const f = dynamic_cast<const This*>(&e);
56 return f && Base::equals(e) &&
57 equal_with_abs_tol(accel_, f->accel_, tol) &&
58 equal_with_abs_tol(gyro_, f->gyro_, tol) &&
59 std::abs(dt_ - f->dt_) < tol;
60 }
61
62 void print(const std::string& s="", const gtsam::KeyFormatter& formatter = gtsam::DefaultKeyFormatter) const override {
63 std::string a = "IMUFactor: " + s;
64 Base::print(a, formatter);
65 gtsam::print((Vector)accel_, "accel");
66 gtsam::print((Vector)gyro_, "gyro");
67 std::cout << "dt: " << dt_ << std::endl;
68 }
69
70 // access
71 const Vector3& gyro() const { return gyro_; }
72 const Vector3& accel() const { return accel_; }
73 Vector6 z() const { return (Vector6() << accel_, gyro_).finished(); }
74
79 Vector evaluateError(const PoseRTV& x1, const PoseRTV& x2,
80 boost::optional<Matrix&> H1 = boost::none,
81 boost::optional<Matrix&> H2 = boost::none) const override {
82 const Vector6 meas = z();
83 if (H1) *H1 = numericalDerivative21<Vector6, PoseRTV, PoseRTV>(
84 std::bind(This::predict_proxy, std::placeholders::_1, std::placeholders::_2, dt_, meas), x1, x2, 1e-5);
85 if (H2) *H2 = numericalDerivative22<Vector6, PoseRTV, PoseRTV>(
86 std::bind(This::predict_proxy, std::placeholders::_1, std::placeholders::_2, dt_, meas), x1, x2, 1e-5);
87 return predict_proxy(x1, x2, dt_, meas);
88 }
89
91 virtual Vector evaluateError(const Pose3& x1, const Pose3& x2,
92 boost::optional<Matrix&> H1 = boost::none,
93 boost::optional<Matrix&> H2 = boost::none) const {
94 assert(false); // no corresponding factor here
95 return Vector6::Zero();
96 }
97
98private:
100 static Vector6 predict_proxy(const PoseRTV& x1, const PoseRTV& x2,
101 double dt, const Vector6& meas) {
102 Vector6 hx = x1.imuPrediction(x2, dt);
103 return meas - hx;
104 }
105};
106
107} // \namespace gtsam
Some functions to compute numerical derivatives.
Non-linear factor base classes.
Pose3 with translational velocity.
Global functions in a separate testing namespace.
Definition: chartTesting.h:28
void print(const Matrix &A, const string &s, ostream &stream)
print without optional string, must specify cout yourself
Definition: Matrix.cpp:155
noiseModel::Base::shared_ptr SharedNoiseModel
Note, deliberately not in noiseModel namespace.
Definition: NoiseModel.h:736
std::uint64_t Key
Integer nonlinear key type.
Definition: types.h:69
std::function< std::string(Key)> KeyFormatter
Typedef for a function to format a key, i.e. to convert it to a string.
Definition: Key.h:35
bool equal_with_abs_tol(const Eigen::DenseBase< MATRIX > &A, const Eigen::DenseBase< MATRIX > &B, double tol=1e-9)
equals with a tolerance
Definition: Matrix.h:84
Definition: Pose3.h:37
This is the base class for all factor types.
Definition: Factor.h:56
Nonlinear factor base class.
Definition: NonlinearFactor.h:43
bool equals(const NonlinearFactor &f, double tol=1e-9) const override
Check if two factors are equal.
Definition: NonlinearFactor.cpp:71
void print(const std::string &s="", const KeyFormatter &keyFormatter=DefaultKeyFormatter) const override
Print.
Definition: NonlinearFactor.cpp:63
A convenient base class for creating your own NoiseModelFactor with 2 variables.
Definition: NonlinearFactor.h:369
Key key1() const
methods to retrieve both keys
Definition: NonlinearFactor.h:401
Class that represents integrating IMU measurements over time for dynamic systems Templated to allow f...
Definition: IMUFactor.h:23
Vector evaluateError(const PoseRTV &x1, const PoseRTV &x2, boost::optional< Matrix & > H1=boost::none, boost::optional< Matrix & > H2=boost::none) const override
Error evaluation with optional derivatives - calculates z - h(x1,x2)
Definition: IMUFactor.h:79
virtual Vector evaluateError(const Pose3 &x1, const Pose3 &x2, boost::optional< Matrix & > H1=boost::none, boost::optional< Matrix & > H2=boost::none) const
dummy version that fails for non-dynamic poses
Definition: IMUFactor.h:91
IMUFactor(const Vector3 &accel, const Vector3 &gyro, double dt, const Key &key1, const Key &key2, const SharedNoiseModel &model)
time between measurements
Definition: IMUFactor.h:37
IMUFactor(const Vector6 &imu_vector, double dt, const Key &key1, const Key &key2, const SharedNoiseModel &model)
Full IMU vector specification.
Definition: IMUFactor.h:42
Vector3 accel_
measurements from the IMU
Definition: IMUFactor.h:31
void print(const std::string &s="", const gtsam::KeyFormatter &formatter=gtsam::DefaultKeyFormatter) const override
Print.
Definition: IMUFactor.h:62
bool equals(const NonlinearFactor &e, double tol=1e-9) const override
Check if two factors are equal.
Definition: IMUFactor.h:54
gtsam::NonlinearFactor::shared_ptr clone() const override
Definition: IMUFactor.h:49
Robot state for use with IMU measurements.
Definition: PoseRTV.h:23
Vector6 imuPrediction(const PoseRTV &x2, double dt) const
Dynamics predictor for both ground and flying robots, given states at 1 and 2 Always move from time 1...
Definition: PoseRTV.cpp:133