As we’ve discussed, control loops are responsible for getting robot attributes like location to desired values.

正如我们所讨论的，控制回路负责使机器人属性（如位置）达到所需值。

Finally, there’s the derivative value, which is the rate of change between the desired and actual values.

最后，还有导数值，它是期望值和实际值之间的变化率。

First is the proportional value, which is the difference between the desired value and the actual value at the most recent instant in time or the present.

首先是 "比例值"，就是 "实际值" 和 "理想值" 差多少，实际值可能有一定滞后，或者是实时的。