# Control Systems Engineering

## Usage

```bash
# PID step response
python3 /workspace/bridge.py scipy_solver '
from scipy import signal
num = [129.6, 324, 81]
den = [15, 131.6, 324, 81]
sys = signal.TransferFunction(num, den)
t, y = signal.step(sys, T=np.linspace(0, 5, 1000))
overshoot = (max(y) - 1.0) * 100
print(f"Overshoot: {overshoot:.1f}%")
print(f"Final value: {y[-1]:.4f}")
'

# Symbolic transfer function
python3 /workspace/bridge.py sympy_math '
s = symbols("s")
G = 100 / (s**2 + 10*s + 100)
print(f"DC gain: {limit(G, s, 0)}")
print(f"Poles: {solve(s**2 + 10*s + 100, s)}")
'
```

For visualization (Bode plots, step response plots):
```bash
python3 /workspace/bridge.py matplotlib_plot 'YOUR_PLOTTING_CODE'
```