Latest version of my quadcopter controller with an LPC1768 and MPU9250.
Currently running on a custom PCB with 30.5 x 30.5mm mounts. There are also 2 PC apps that go with the software; one to set up the PID controller and one to balance the motors and props. If anyone is interested, send me a message and I'll upload them.
Filters/LPfilter.cpp@8:981f7e2365b6, 2018-07-31 (annotated)
- Committer:
- Anaesthetix
- Date:
- Tue Jul 31 20:36:57 2018 +0000
- Revision:
- 8:981f7e2365b6
- Parent:
- 7:d86c41443f6d
Switched from Madgwick to Mahony as I'm having trouble with slow oscillations caused by the madgwick filter. Fixed an error on the PID algorithm also.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
Anaesthetix | 4:fab65ad01ab4 | 1 | // Coded by Erik van de Coevering |
Anaesthetix | 7:d86c41443f6d | 2 | // DSP-style low-pass IIR filters designed with Matlab's FDAtool. |
Anaesthetix | 4:fab65ad01ab4 | 3 | // For information on how to implement these filters, check this pdf: http://spinlab.wpi.edu/courses/ece4703_2009/how_to_interpret_matlab_dfii_sos.pdf |
Anaesthetix | 4:fab65ad01ab4 | 4 | |
Anaesthetix | 0:0929d3d566cf | 5 | #include "LPfilter.h" |
Anaesthetix | 7:d86c41443f6d | 6 | /* |
Anaesthetix | 0:0929d3d566cf | 7 | float LPfilter::run(float input) { |
Anaesthetix | 0:0929d3d566cf | 8 | filterbuffer[2] = filterbuffer[1]; |
Anaesthetix | 0:0929d3d566cf | 9 | filterbuffer[1] = filterbuffer[0]; |
Anaesthetix | 0:0929d3d566cf | 10 | filterbuffer[0] = input*LP_A + filterbuffer[1]*LP_B + filterbuffer[2]*LP_C; |
Anaesthetix | 0:0929d3d566cf | 11 | |
Anaesthetix | 0:0929d3d566cf | 12 | out = filterbuffer[0]*LP_D + filterbuffer[1]*LP_E + filterbuffer[2]*LP_F; |
Anaesthetix | 0:0929d3d566cf | 13 | return out; |
Anaesthetix | 0:0929d3d566cf | 14 | } |
Anaesthetix | 0:0929d3d566cf | 15 | |
Anaesthetix | 0:0929d3d566cf | 16 | float LPfilter2::run(float input) { |
Anaesthetix | 0:0929d3d566cf | 17 | filterbuffer1[2] = filterbuffer1[1]; |
Anaesthetix | 0:0929d3d566cf | 18 | filterbuffer1[1] = filterbuffer1[0]; |
Anaesthetix | 0:0929d3d566cf | 19 | filterbuffer1[0] = input*0.003762202981699 + filterbuffer1[1]*1.893415601023 + filterbuffer1[2]*-0.9084644129493; |
Anaesthetix | 0:0929d3d566cf | 20 | |
Anaesthetix | 0:0929d3d566cf | 21 | out_temp = filterbuffer1[0] + filterbuffer1[1]*2.0f + filterbuffer1[2]; |
Anaesthetix | 0:0929d3d566cf | 22 | |
Anaesthetix | 0:0929d3d566cf | 23 | filterbuffer2[2] = filterbuffer2[1]; |
Anaesthetix | 0:0929d3d566cf | 24 | filterbuffer2[1] = filterbuffer2[0]; |
Anaesthetix | 0:0929d3d566cf | 25 | filterbuffer2[0] = out_temp*0.003533495923378 + filterbuffer2[1]*1.778313488139 + filterbuffer2[2]*-0.7924474718329; |
Anaesthetix | 0:0929d3d566cf | 26 | |
Anaesthetix | 0:0929d3d566cf | 27 | out = filterbuffer2[0] + filterbuffer2[1]*2.0f + filterbuffer2[2]; |
Anaesthetix | 0:0929d3d566cf | 28 | return out; |
Anaesthetix | 0:0929d3d566cf | 29 | } |
Anaesthetix | 0:0929d3d566cf | 30 | |
Anaesthetix | 0:0929d3d566cf | 31 | float LPfilter2_1::run(float input) { |
Anaesthetix | 0:0929d3d566cf | 32 | filterbuffer1[2] = filterbuffer1[1]; |
Anaesthetix | 0:0929d3d566cf | 33 | filterbuffer1[1] = filterbuffer1[0]; |
Anaesthetix | 0:0929d3d566cf | 34 | filterbuffer1[0] = input*0.007954132308248 + filterbuffer1[1]*1.836787188551 + filterbuffer1[2]*-0.8686037177835; |
Anaesthetix | 0:0929d3d566cf | 35 | |
Anaesthetix | 0:0929d3d566cf | 36 | out_temp = filterbuffer1[0] + filterbuffer1[1]*2.0f + filterbuffer1[2]; |
Anaesthetix | 0:0929d3d566cf | 37 | |
Anaesthetix | 0:0929d3d566cf | 38 | filterbuffer2[2] = filterbuffer2[1]; |
Anaesthetix | 0:0929d3d566cf | 39 | filterbuffer2[1] = filterbuffer2[0]; |
Anaesthetix | 0:0929d3d566cf | 40 | filterbuffer2[0] = out_temp*0.007277930990548 + filterbuffer2[1]*1.680637168775 + filterbuffer2[2]*-0.7097488927369; |
Anaesthetix | 0:0929d3d566cf | 41 | |
Anaesthetix | 0:0929d3d566cf | 42 | out = filterbuffer2[0] + filterbuffer2[1]*2.0f + filterbuffer2[2]; |
Anaesthetix | 0:0929d3d566cf | 43 | return out; |
Anaesthetix | 0:0929d3d566cf | 44 | } |
Anaesthetix | 7:d86c41443f6d | 45 | */ |
Anaesthetix | 7:d86c41443f6d | 46 | //8th order IIR filter, with Fs = 1500Hz and Fc = 45Hz |
Anaesthetix | 0:0929d3d566cf | 47 | |
Anaesthetix | 7:d86c41443f6d | 48 | float LPfilter8::run(float input) { |
Anaesthetix | 7:d86c41443f6d | 49 | filterbuffer1[2] = filterbuffer1[1]; |
Anaesthetix | 7:d86c41443f6d | 50 | filterbuffer1[1] = filterbuffer1[0]; |
Anaesthetix | 7:d86c41443f6d | 51 | filterbuffer1[0] = input*0.008544036438708 + filterbuffer1[1]*1.895289756537 + filterbuffer1[2]*-0.9294659022914; |
Anaesthetix | 7:d86c41443f6d | 52 | |
Anaesthetix | 7:d86c41443f6d | 53 | out_temp1 = filterbuffer1[0] + filterbuffer1[1]*2.0f + filterbuffer1[2]; |
Anaesthetix | 7:d86c41443f6d | 54 | |
Anaesthetix | 7:d86c41443f6d | 55 | filterbuffer2[2] = filterbuffer2[1]; |
Anaesthetix | 7:d86c41443f6d | 56 | filterbuffer2[1] = filterbuffer2[0]; |
Anaesthetix | 7:d86c41443f6d | 57 | filterbuffer2[0] = out_temp1*0.008021326615853 + filterbuffer2[1]*1.779339107215 + filterbuffer2[2]*-0.811424413678; |
Anaesthetix | 7:d86c41443f6d | 58 | |
Anaesthetix | 7:d86c41443f6d | 59 | out_temp2 = filterbuffer2[0] + filterbuffer2[1]*2.0f + filterbuffer2[2]; |
Anaesthetix | 7:d86c41443f6d | 60 | |
Anaesthetix | 7:d86c41443f6d | 61 | filterbuffer3[2] = filterbuffer3[1]; |
Anaesthetix | 7:d86c41443f6d | 62 | filterbuffer3[1] = filterbuffer3[0]; |
Anaesthetix | 7:d86c41443f6d | 63 | filterbuffer3[0] = out_temp2*0.007662537043122 + filterbuffer3[1]*1.699750237618 + filterbuffer3[2]*-0.7304003857905; |
Anaesthetix | 7:d86c41443f6d | 64 | |
Anaesthetix | 7:d86c41443f6d | 65 | out_temp3 = filterbuffer3[0] + filterbuffer3[1]*2.0f + filterbuffer3[2]; |
Anaesthetix | 7:d86c41443f6d | 66 | |
Anaesthetix | 7:d86c41443f6d | 67 | filterbuffer4[2] = filterbuffer4[1]; |
Anaesthetix | 7:d86c41443f6d | 68 | filterbuffer4[1] = filterbuffer4[0]; |
Anaesthetix | 7:d86c41443f6d | 69 | filterbuffer4[0] = out_temp3*0.007481430998498 + filterbuffer4[1]*1.659576201179 + filterbuffer4[2]*-0.6895019251732; |
Anaesthetix | 7:d86c41443f6d | 70 | |
Anaesthetix | 7:d86c41443f6d | 71 | out = filterbuffer4[0] + filterbuffer4[1]*2.0f + filterbuffer4[2]; |
Anaesthetix | 7:d86c41443f6d | 72 | |
Anaesthetix | 7:d86c41443f6d | 73 | return out; |
Anaesthetix | 7:d86c41443f6d | 74 | } |