Analog PID controller (transferfunction questions)
You need 3 more resistors of value R3 to make this add the components equally. This is a textbook parallel PID controller. Assuming R1 = R2** 

\$\tau_i\$ is R3*C1

\$\tau_d\$ is R4*C2

While you can certainly build this, it has a number of problems. The derivative will cause noise problems. Usually a filter has to be placed in front of the differentiator if you really need the derivative function (it's often not necessary and causes more problems than not). 

You also have to consider saturation in each of the three terms as well as the output. As part of that consideration of saturation, if the integrator continues to integrate while the output is saturated you'll have integrator windup, which will usually cause a lot of over/undershoot, especially at start-up.  

** If they are not equal, or if the summing resistors are different from R3 then it will effectively scale each of the three terms. You can probably see that that's (ideally) the same as scaling the time constants. In practice, you cannot use an integration capacitor 1/100 the size and use a large summing resistor because the op-amp will saturate before it can apply enough integral action to force the output over the whole range.