A proportional controller ($K_p$)will have the effect of reducing the rise time and will reduce but never eliminate the steady-state error. An integral control w($K_i$) ill have the effect of eliminating the steady-state error for a constant or step input, but it may make the transient response slower. A derivative control w($K_d$) ill have the effect of increasing the stability of the system, reducing the overshoot, and improving the transient response.