Simbody  3.8
Force_MobilityLinearSpring.h
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1 #ifndef SimTK_SIMBODY_FORCE_MOBILITY_LINEAR_SPRING_H_
2 #define SimTK_SIMBODY_FORCE_MOBILITY_LINEAR_SPRING_H_
3 
4 /* -------------------------------------------------------------------------- *
5  * Simbody(tm) *
6  * -------------------------------------------------------------------------- *
7  * This is part of the SimTK biosimulation toolkit originating from *
8  * Simbios, the NIH National Center for Physics-Based Simulation of *
9  * Biological Structures at Stanford, funded under the NIH Roadmap for *
10  * Medical Research, grant U54 GM072970. See https://simtk.org/home/simbody. *
11  * *
12  * Portions copyright (c) 2008-13 Stanford University and the Authors. *
13  * Authors: Peter Eastman, Michael Sherman *
14  * Contributors: *
15  * *
16  * Licensed under the Apache License, Version 2.0 (the "License"); you may *
17  * not use this file except in compliance with the License. You may obtain a *
18  * copy of the License at http://www.apache.org/licenses/LICENSE-2.0. *
19  * *
20  * Unless required by applicable law or agreed to in writing, software *
21  * distributed under the License is distributed on an "AS IS" BASIS, *
22  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. *
23  * See the License for the specific language governing permissions and *
24  * limitations under the License. *
25  * -------------------------------------------------------------------------- */
26 
27 #include "SimTKcommon.h"
28 #include "simbody/internal/Force.h"
29 
35 namespace SimTK {
36 
50 public:
67  const MobilizedBody& mobod,
68  MobilizerQIndex whichQ,
69  Real defaultStiffness,
70  Real defaultQZero);
71 
75 
89 
90 
105 
114 
129  Real stiffness) const;
130 
146  Real qZero) const;
147 
152  Real getStiffness(const State& state) const;
153 
158  Real getQZero(const State& state) const;
159 
168  const MobilizedBody& mobod,
169  int whichQ,
170  Real defaultStiffness,
171  Real defaultQZero)
172  { // Invoke the other constructor.
173  new(this) MobilityLinearSpring(forces, mobod, MobilizerQIndex(whichQ),
174  defaultStiffness, defaultQZero);
175  }
180  MobilityLinearSpringImpl, Force);
182 };
183 
184 } // namespace SimTK
185 
186 #endif // SimTK_SIMBODY_FORCE_MOBILITY_LINEAR_SPRING_H_
#define SimTK_INSERT_DERIVED_HANDLE_DECLARATIONS(DERIVED, DERIVED_IMPL, PARENT)
Definition: PrivateImplementation.h:343
Includes internal headers providing declarations for the basic SimTK Core classes,...
#define SimTK_SIMBODY_EXPORT
Definition: Simbody/include/simbody/internal/common.h:68
A linear spring that acts along or around a mobility coordinate to apply a generalized force there.
Definition: Force_MobilityLinearSpring.h:49
Real getStiffness(const State &state) const
Return the value for the spring's stiffness k that is stored in the given state.
MobilityLinearSpring(GeneralForceSubsystem &forces, const MobilizedBody &mobod, int whichQ, Real defaultStiffness, Real defaultQZero)
Deprecated: Alternate signature for backwards compatibility – for safety you should prefer using the ...
Definition: Force_MobilityLinearSpring.h:167
MobilityLinearSpring & setDefaultStiffness(Real defaultStiffness)
Provide a new value for the default stiffness k of this spring.
Real getDefaultStiffness() const
Return the default value for the spring's stiffness k.
MobilityLinearSpring(GeneralForceSubsystem &forces, const MobilizedBody &mobod, MobilizerQIndex whichQ, Real defaultStiffness, Real defaultQZero)
Create a MobilityLinearSpring force element on a particular generalized coordinate.
MobilityLinearSpring()
Default constructor creates an empty handle that can be assigned to refer to any MobilityLinearSpring...
Definition: Force_MobilityLinearSpring.h:74
const MobilityLinearSpring & setQZero(State &state, Real qZero) const
Change the value of the spring zero length in the given state; this may differ from the default value...
const MobilityLinearSpring & setStiffness(State &state, Real stiffness) const
Change the value of the spring stiffness in the given state; this may differ from the default value s...
Real getDefaultQZero() const
Return the default value for the spring's zero position q0.
MobilityLinearSpring & setDefaultQZero(Real defaultQZero)
Provide a new value for the zero position q0 of this spring, at which position the spring force will ...
Real getQZero(const State &state) const
Return the value for the spring zero position q0 that is stored in the given state.
This is the base class from which all Force element handle classes derive.
Definition: Force.h:50
This is a concrete subsystem which can apply arbitrary forces to a MultibodySystem.
Definition: GeneralForceSubsystem.h:47
A MobilizedBody is Simbody's fundamental body-and-joint object used to parameterize a system's motion...
Definition: MobilizedBody.h:169
The Mobilizer associated with each MobilizedBody, once modeled, has a specific number of generalized ...
This object is intended to contain all state information for a SimTK::System, except topological info...
Definition: State.h:280
This is the top-level SimTK namespace into which all SimTK names are placed to avoid collision with o...
Definition: Assembler.h:37
SimTK_Real Real
This is the default compiled-in floating point type for SimTK, either float or double.
Definition: SimTKcommon/include/SimTKcommon/internal/common.h:607