diff --git a/flight/Libraries/math/sin_lookup.c b/flight/Libraries/math/sin_lookup.c index 575f171d3..2a5508fce 100644 --- a/flight/Libraries/math/sin_lookup.c +++ b/flight/Libraries/math/sin_lookup.c @@ -28,9 +28,14 @@ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include "openpilot.h" #include "math.h" +#include "stdbool.h" #include "stdint.h" +#ifdef FLASH_TABLE + /** Version of the code which precomputes the lookup table in flash **/ + // This is a precomputed sin lookup table over 90 degrees that const float sin_table[] = { 0.000000f,0.017452f,0.034899f,0.052336f,0.069756f,0.087156f,0.104528f,0.121869f,0.139173f,0.156434f, @@ -44,6 +49,11 @@ 0.984808f,0.987688f,0.990268f,0.992546f,0.994522f,0.996195f,0.997564f,0.998630f,0.999391f,0.999848f }; +int sin_lookup_initalize() +{ + return 0; +} + /** * Use the lookup table to return sine(angle) where angle is in radians * to save flash this cheats and uses trig functions to only save @@ -66,6 +76,46 @@ float sin_lookup_deg(float angle) return 0; } +#else +/** Version of the code which allocates the lookup table in heap **/ + +const int SIN_RESOLUTION = 180; + +static float *sin_table; +int sin_lookup_initalize() +{ + // Previously initialized + if (sin_table) + return 0; + + sin_table = (float *) pvPortMalloc(sizeof(float) * SIN_RESOLUTION); + if (sin_table == NULL) + return -1; + + for(uint32_t i = 0; i < 180; i++) + sin_table[i] = sinf((float)i * 2 * M_PI / 360.0f); + + return 0; +} + + + +/** + * Uses the lookup table to calculate sine (angle is in degrees) + * @param[in] angle in degrees + * @returns sin(angle) + */ +float sin_lookup_deg(float angle) { + int i_ang = ((int32_t)angle) % 360; + if (i_ang > 180) + return - sin_table[i_ang-180]; + else + return sin_table[i_ang]; +} + +#endif + + /** * Get cos(angle) using the sine lookup table * @param[in] angle Angle in degrees diff --git a/flight/Libraries/math/sin_lookup.h b/flight/Libraries/math/sin_lookup.h index 0e0edb274..adc29f66a 100644 --- a/flight/Libraries/math/sin_lookup.h +++ b/flight/Libraries/math/sin_lookup.h @@ -31,6 +31,7 @@ #ifndef SIN_LOOKUP_H #define SIN_LOOKUP_H +int sin_lookup_initalize(); float sin_lookup_deg(float angle); float cos_lookup_deg(float angle); float sin_lookup_rad(float angle); diff --git a/flight/Modules/Stabilization/relay_tuning.c b/flight/Modules/Stabilization/relay_tuning.c index 5dc538b4a..0f0bb9d55 100644 --- a/flight/Modules/Stabilization/relay_tuning.c +++ b/flight/Modules/Stabilization/relay_tuning.c @@ -101,11 +101,11 @@ int stabilization_relay_rate(float error, float *output, int axis, bool reinit) // Project the error onto a sine and cosine of the same frequency // to accumulate the average amplitude int32_t dT = thisTime - lastHighTime; - int32_t phase = (360 * dT) / relay.Period[axis]; + float phase = ((float)360 * (float)dT) / relay.Period[axis]; if(phase >= 360) phase = 0; accum_sin += sin_lookup_deg(phase) * error; - accum_cos += cos_lookup_deg(phase) * error; + accum_cos += sin_lookup_deg(phase + 90) * error; accumulated ++; // Make sure we've had enough time since last transition then check for a change in the output diff --git a/flight/Modules/Stabilization/stabilization.c b/flight/Modules/Stabilization/stabilization.c index 188f556c8..c4cc801e8 100644 --- a/flight/Modules/Stabilization/stabilization.c +++ b/flight/Modules/Stabilization/stabilization.c @@ -47,6 +47,7 @@ // Math libraries #include "CoordinateConversions.h" #include "pid.h" +#include "sin_lookup.h" // Includes for various stabilization algorithms #include "relay_tuning.h" @@ -117,12 +118,15 @@ int32_t StabilizationInitialize() // Initialize variables StabilizationSettingsInitialize(); ActuatorDesiredInitialize(); - RelayTuningSettingsInitialize(); - RelayTuningInitialize(); #if defined(DIAGNOSTICS) RateDesiredInitialize(); #endif - + + // Code required for relay tuning + sin_lookup_initalize(); + RelayTuningSettingsInitialize(); + RelayTuningInitialize(); + return 0; }