Velocity Profile Calculator — limited jerk 1D motion

Main takes 4 parameters:

• displacement expected;
• velocity limit;
• acceleration limit;
• jerk limit.

From the parameters calculate_time_1d() then calculates time of each of the 7 constant jerk segments to arrive at a continuous acceleration curve for movement, also known as S-curve.

The time results can generate a csv with all motion profile curves using generate_curve_1d(), to be visualized with the Python script Plot.py.

Requirements:

1. GCC
2. Python3 with Matplotlib and Pandas installed

Flow chart:

Compile:

>> gcc main.c -o main.o  -std=c99 -Wall -pedantic

Run:

main.o takes 4 arguments, displacent, maximum velocity, maximum acceleration and maximum jerk:

>> ./main.o  0.5 0.3 0.3 0.6 && python plot.py                  

Displacement is       0.500000 m   
Velocity limit        0.300000 m/s 
Acceleration limit is 0.300000 m/s2
Jerk limit is         0.600000 m/s3

Start calculate_time_1d(): 
time[0] = 0.500000 
velocity1 = 0.075000

velocity1 = 0.075000 
velocity2 = 0.225000 
velocity3 = 0.300000 

S1+S2+S3 = 0.012500+0.075000+0.137500 = 0.225000 
S4 = 0.050000 
velocity4 = 0.000000 


Time  0: 0.500000 s
Time  1: 0.500000 s
Time  2: 0.500000 s
Time  3: 0.166667 s
Time  4: 0.500000 s
Time  5: 0.500000 s
Time  6: 0.500000 s

Total time is 3.166667
File output.csv generated.

Tests

To cover 100% of the code, 4 different inputs are required based on the flow chart. The tests may be executed with ./test.sh or manually.

01 — Maximum Velocity & Acceleration (V₁ ≤ V_max/2)

>> ./main.o  1 0.3 0.3 0.6 && python plot.py

02 — Maximum Velocity (V₁ > V_max/2)

>> ./main.o  0.4 0.1 0.3 0.6 && python plot.py

03 — Maximum Acceleration (S1 + S2 + S3 > S/2)

>> ./main.o  0.4 0.3 0.3 0.6 && python plot.py

04 — Limited Velocity & Acceleration (S1 + S3 > S/2)

>> ./main.o  0.01 0.166 0.5 0.1 && python plot.py

REFERENCE

Ng Yu Ki (2008). "A New Velocity Profile Generation for High-Efficiency CNC Machining Applications."