libhybrid.h File Reference

#include "librk4.h"

Go to the source code of this file.

Data Structures
struct	hyb_opts
	Options structure for the hybrid system. More...

Macros
#define	HYB_FLOAT_TYPE   double
#define	RK4_FLOAT_TYPE   HYB_FLOAT_TYPE
#define	HYB_JUMP_LOGIC   1
	Jump logic implementation. More...
#define	HYB_GET_OPTS(S)   ((hyb_opts *)S)
#define	HYB_SEND_OPTS(S)   ((void *)S)

Typedefs
typedef HYB_FLOAT_TYPE	hyb_float
typedef enum hyb_bool	hyb_bool
	libhybrid boolean type is actually an enum More...
typedef void(*	hyb_flow_map) (hyb_float *xdot, hyb_float t, hyb_float j, const hyb_float *x, const hyb_float *u, const hyb_float **p)
	Callback definition for the Flow Map. More...
typedef void(*	hyb_jump_map) (hyb_float *xp, hyb_float t, hyb_float j, const hyb_float *x, const hyb_float *u, const hyb_float **p)
	Callback definition for the Jump Map. More...
typedef hyb_bool(*	hyb_jump_set) (hyb_float t, hyb_float j, const hyb_float *x, const hyb_float *u, const hyb_float **p)
	Callback definition for the Jump Set. More...
typedef hyb_bool(*	hyb_flow_set) (hyb_float t, hyb_float j, const hyb_float *x, const hyb_float *u, const hyb_float **p)
	Callback definition for the Flow Set. More...
typedef void(*	hyb_out_map) (hyb_float *y, hyb_float t, hyb_float j, const hyb_float *x, const hyb_float *u, const hyb_float **p)
typedef struct hyb_opts	hyb_opts
	Options structure for the hybrid system. More...
typedef enum hyb_errorcode	hyb_errorcode

Enumerations
enum	hyb_bool { hyb_false = 0, hyb_true }
	libhybrid boolean type is actually an enum More...
enum	hyb_errorcode {   HYB_SUCCESS = 0, HYB_EMALLOC, HYB_NULLPTR, HYB_GENERIC,   HYB_TLIMIT, HYB_JLIMIT, HYB_NOJUMP }

Functions
hyb_errorcode	hyb_main_loop (hyb_opts *opts, hyb_float *y, hyb_float *xp, hyb_float tau, const hyb_float *x, const hyb_float *u, const hyb_float **p)
	Hybrid system main loop. More...
void	hyb_flow_map_wrapper (hyb_float *dx, hyb_float tau, const hyb_float *x, const hyb_float *u, const hyb_float **p, void *vopts)
	Internal callback for discretization step. More...

---

Data Structure Documentation

struct hyb_opts

Options structure for the hybrid system.

Definition at line 242 of file libhybrid.h.

Data Fields
hyb_flow_set	C	Flow set function pointer
hyb_jump_set	D	Jump set function pointer
hyb_flow_map	F	Flow map function pointer
hyb_jump_map	J	Jump map function pointer
hyb_float	J_horizon	Maximum discrete step horizon
hyb_float	T_horizon	Maximum continuous time horizon
hyb_float	Ts	Time step
size_t	x_size	State size
hyb_out_map	Y	Output map function pointer
size_t	y_size	Output size

Macro Definition Documentation

#define HYB_FLOAT_TYPE   double

Precision defaut is double

Definition at line 60 of file libhybrid.h.

#define HYB_GET_OPTS

(

S

)

((hyb_opts *)S)

Converts the void pointer in option struct pointer. For internal use only

Definition at line 255 of file libhybrid.h.

#define HYB_JUMP_LOGIC   1

Jump logic implementation.

There are two possible jump logic implementation:

1. Precedence on the jump map (default)
2. Precedence on the flow map

Definition at line 236 of file libhybrid.h.

#define HYB_SEND_OPTS

(

S

)

((void *)S)

Converts the option struct in void pointer. For internal use only

Definition at line 256 of file libhybrid.h.

#define RK4_FLOAT_TYPE   HYB_FLOAT_TYPE

Forcing consistent types

Definition at line 64 of file libhybrid.h.

Typedef Documentation

typedef enum hyb_bool hyb_bool

libhybrid boolean type is actually an enum

This enum is the returned value for the Jump Set function and the Flow Set function.

typedef enum hyb_errorcode hyb_errorcode

typedef HYB_FLOAT_TYPE hyb_float

Precision typedef, used in library

Definition at line 62 of file libhybrid.h.

typedef void(* hyb_flow_map) (hyb_float *xdot, hyb_float t, hyb_float j, const hyb_float *x, const hyb_float *u, const hyb_float **p)

Callback definition for the Flow Map.

The callback stores the output in the first pointer (xdot). The function does not need to allocate nor free the output vector, but may overflow if exceedes the dimension that is declared in the hyb_opts structure. Please notice that this function will be discretized in a Runge Kutta 4 integrator: librk4.h. When accessing an element of the parameter, please remember that the implementation keeps in mind a MATLAB-like interface. If the parameters (in MATLAB) are passed like:

f(t, x, u, p1, [p2, p3])

then, in the C code, p1, p2 and p3 may be accessed in p as:

rk4_float p1, p2, p3;
p1 = p[0][0];
p2 = p[1][0];
p3 = p[1][1];

Parameters

xdot	an array in which the result will be stored
t	is the current time
j	is the discrete time
x	a constant array with the current state
u	a constant array with current input
p	a pointer to arrays of parameters. This allows the compatibility with the MATLAB System Identification Toolbox

Definition at line 107 of file libhybrid.h.

typedef hyb_bool(* hyb_flow_set) (hyb_float t, hyb_float j, const hyb_float *x, const hyb_float *u, const hyb_float **p)

Callback definition for the Flow Set.

The callback should return hyb_true if the combination of state, input and parameters enters the flow set. When accessing an element of the parameter, please remember that the implementation keeps in mind a MATLAB-like interface. If the parameters (in MATLAB) are passed like:

f(t, x, u, p1, [p2, p3])

then, in the C code, p1, p2 and p3 may be accessed in p as:

rk4_float p1, p2, p3;
p1 = p[0][0];
p2 = p[1][0];
p3 = p[1][1];

Parameters

t	is the current time
j	is the discrete time
x	a constant array with the current state
u	a constant array with current input
p	a pointer to arrays of parameters. This allows the compatibility with the MATLAB System Identification Toolbox

Definition at line 223 of file libhybrid.h.

typedef void(* hyb_jump_map)(hyb_float *xp, hyb_float t, hyb_float j, const hyb_float *x, const hyb_float *u, const hyb_float **p)

Callback definition for the Jump Map.

Callback definition for the Output Map.

The callback stores the output in the first pointer (xp). The function does not need to allocate nor free the output vector, but may overflow if exceedes the dimension that is declared in the hyb_opts structure. When accessing an element of the parameter, please remember that the implementation keeps in mind a MATLAB-like interface. If the parameters (in MATLAB) are passed like:

f(t, x, u, p1, [p2, p3])

then, in the C code, p1, p2 and p3 may be accessed in p as:

rk4_float p1, p2, p3;
p1 = p[0][0];
p2 = p[1][0];
p3 = p[1][1];

Parameters

xp	an array in which the result will be stored
t	is the current time
j	is the discrete time
x	a constant array with the current state
u	a constant array with current input
p	a pointer to arrays of parameters. This allows the compatibility with the MATLAB System Identification Toolbox

The callback stores the output in the first pointer (y). The function does not need to allocate nor free the input vector, but may overflow if exceedes the dimension that is declared in the hyb_opts structure. When accessing an element of the parameter, please remember that the implementation keeps in mind a MATLAB-like interface. If the parameters (in MATLAB) are passed like:

f(t, x, u, p1, [p2, p3])

then, in the C code, p1, p2 and p3 may be accessed in p as:

rk4_float p1, p2, p3;
p1 = p[0][0];
p2 = p[1][0];
p3 = p[1][1];

Parameters

xp	an array in which the result will be stored
t	is the current time
j	is the discrete time
x	a constant array with the current state
u	a constant array with current input
p	a pointer to arrays of parameters. This allows the compatibility with the MATLAB System Identification Toolbox

Definition at line 137 of file libhybrid.h.

typedef hyb_bool(* hyb_jump_set) (hyb_float t, hyb_float j, const hyb_float *x, const hyb_float *u, const hyb_float **p)

Callback definition for the Jump Set.

The callback should return hyb_true if the combination of state, input and parameters enters the jump set. When accessing an element of the parameter, please remember that the implementation keeps in mind a MATLAB-like interface. If the parameters (in MATLAB) are passed like:

f(t, x, u, p1, [p2, p3])

then, in the C code, p1, p2 and p3 may be accessed in p as:

rk4_float p1, p2, p3;
p1 = p[0][0];
p2 = p[1][0];
p3 = p[1][1];

Parameters

t	is the current time
j	is the discrete time
x	a constant array with the current state
u	a constant array with current input
p	a pointer to arrays of parameters. This allows the compatibility with the MATLAB System Identification Toolbox

Definition at line 195 of file libhybrid.h.

typedef struct hyb_opts hyb_opts

Options structure for the hybrid system.

typedef void(* hyb_out_map) (hyb_float *y, hyb_float t, hyb_float j, const hyb_float *x, const hyb_float *u, const hyb_float **p)

Definition at line 226 of file libhybrid.h.

Enumeration Type Documentation

enum hyb_bool

libhybrid boolean type is actually an enum

This enum is the returned value for the Jump Set function and the Flow Set function.

Enumerator
hyb_false	False value
hyb_true	True value

Definition at line 73 of file libhybrid.h.

                      {
  hyb_false = 0, 
  hyb_true 
} hyb_bool;

enum hyb_errorcode

Enumerator
HYB_SUCCESS	Step seems good!
HYB_EMALLOC	During the step there was an allocation error
HYB_NULLPTR	Reveived a null pointer
HYB_GENERIC	Unknown error generated
HYB_TLIMIT	Reached time limit
HYB_JLIMIT	Reached step limit
HYB_NOJUMP	Invalid jump condition (Both c = 0 and d = 0). Not implemented

Definition at line 258 of file libhybrid.h.

                           {
  HYB_SUCCESS = 0, 
  HYB_EMALLOC,     
  HYB_NULLPTR,     
  HYB_GENERIC,     
  HYB_TLIMIT,      
  HYB_JLIMIT,      
  HYB_NOJUMP       
} hyb_errorcode;

Function Documentation

void hyb_flow_map_wrapper	(	hyb_float *	dx,
		hyb_float	tau,
		const hyb_float *	x,
		const hyb_float *	u,
		const hyb_float **	p,
		void *	vopts
	)

Internal callback for discretization step.

Warning

This is for internal use only, do not use directly. This callback has been implemented in order to respond to rk4_ode requirements.

Parameters

dx	output of the callback
tau	hybrid time step, is probably different with respect to the evolution time
x	the current state, contains time and jump state
u	the current control
p	the parameter vector of vectors
vopts	a void pointer for user space, is used for passing by the options struct

Definition at line 66 of file libhybrid.c.

                                                                                                                                  {
  dx[0] = 1.0;
  dx[1] = 0.0;
  HYB_GET_OPTS(vopts)->F(dx + 2, x[0], x[1], x + 2, u, p);
}

hyb_errorcode hyb_main_loop	(	hyb_opts *	opts,
		hyb_float *	y,
		hyb_float *	xp,
		hyb_float	tau,
		const hyb_float *	x,
		const hyb_float *	u,
		const hyb_float **	p
	)

Hybrid system main loop.

The main loop of the hybrid system performs the following operations:

1. Check if stop criteria is reached
2. Check if the jump conditions are respected.
   • if jump is requsted, it enters a loop of update until no jump should be performed
   • else the execution continues
3. The

   Parameters

   opts	pointer to an option structure
   y	vector that will contain the next output. It must be already allocated
   xp	vector that will contain the next state (already integrated in case of flowing step). It must be already allocated
   tau	integration engine time
   x	current state
   u	current input
   p	parameter vector

   Returns

   an exit codes, as described in hyb_errorcode

Definition at line 31 of file libhybrid.c.

                                                                                                                                                     {

  opts->Y(y, x[0], x[1], x + 2, u, p);

  if (x[0] >= opts->T_horizon)
    return HYB_TLIMIT;
  if (x[1] >= opts->J_horizon)
    return HYB_JLIMIT;

  hyb_bool d = opts->D(x[0], x[1], x + 2, u, p);
  #if HYB_JUMP_LOGIC == 2
    hyb_bool c = opts->C(x[0], x[1], x + 2, u, p);
  #endif

  hyb_bool it_jumps;
  #if HYB_JUMP_LOGIC == 1
    it_jumps = d;
  #elif HYB_JUMP_LOGIC == 2
    it_jumps = d && !c;
  #endif

  if (it_jumps) {
    xp[0] = x[0];
    xp[1] = x[1] + 1.0;
    opts->J(xp + 2, x[0], x[1], x + 2, u, p);
  } else {
    rk4_opts rk4_o = { opts->Ts, (opts->x_size + 2), hyb_flow_map_wrapper };
    rk4_errorcode rk4_ret = rk4(&rk4_o, xp, tau, x, u, p, HYB_SEND_OPTS(opts));
    if (rk4_ret) {
      return (hyb_errorcode)rk4_ret;
    }
  }
  return HYB_SUCCESS;
}