伪代码。
while(true){
val height = getHeight(); // from sensor
// Get the difference between the current height and
// the TARGET height. Positive values mean too low
// while negative values mean too high
val offset = TARGET_VALUE - height;
// Set the power to some direct ratio of the offset
// When the baloon is at 0 height, the offset should
// be relatively high, so the power will be set
// high. If the offset is negative, the power will be
// set negative from the current power.
setPower(offset);// I'll leave it up to you to figure out the ratio
}