1. A robot control method of a robot control apparatus for controlling a robot arm to be driven by transmitting a drive force to each of multiple joints from each of drive sources corresponding thereto via a transmitting component so that the robot arm follows a specified trajectory, the control being carried out based on an instruction value to be instructed to each of the drive sources, the robot control method comprising: storing, in a storage unit, constraint conditions including a constraint value of a jerk for each of the multiple joints; calculating, by said robot control apparatus, the constraint conditions differently for each of multiple spaces into which a movable range of the robot arm is divided, so that a load torque to be applied to the transmitting component falls within an allowable range; generating, by a calculating unit, the instruction value based on the specified trajectory of the robot arm by solving an optimization problem that uses the constraint conditions stored in the storage unit as an inequality constraint; sending the instruction value to a servo control unit configured to control the drive source in the robot arm; and controlling the robot arm based on the instruction value.