It's not clear to me when the motor should be switched on. You should give a better description.
But this should give the idea how to check all sensors. If all sensors measure more than 57cm, the motor will be activated.
void Sensor_Trigger()
{
bool isMatch = true;
for (int sonarCnt = 0; sonarCnt < SONAR_NUM; sonarCnt++)
{
if (sonar[sonarCnt].ping_cm() <= 57)
{
isMatch = false;
}
}
// if all sensors measure more than 57
if (isMatch == true)
{
Motor_Driver_1_RS.backward();
Serial.println("Motor Driver 1 L/S is ON - Forward");
delay(500);
Motor_Driver_1_RS.stop();
Serial.println("Motor Driver 1 L/S is OFF");
}
}