Patent ID: 7711456

Claim:
A safe control device for commanding an actuator movement comprising: at least two independent calculation chains, a mixing instructions circuit; and a power stage, wherein each calculation chain is configured to deliver a direction of movement instruction and a speed of movement instruction for the actuator, the instructions being transmitted to the mixing instructions circuit in order to generate a primary actuator movement command comprising modulated pulse trains, the power stage receiving the primary movement command and delivering a power movement command to the actuator, the mixing instructions circuit configured to compare the direction of movement instructions and the speed of movement instructions in pairs in order to generate the primary actuator movement command, the safe control device further comprising an exchange module configured to exchange information between the calculation chains, wherein the information exchanged allows a temporal synchronization of the speed instructions before the speed instructions are delivered to the mixing instructions circuit; wherein the direction of movement instructions, the speed of movement instructions, and the primary actuator movement command are transmitted as four discrete two-state Boolean values (HW_WAY 1 , HW_WAY 2 , HW_SPEED 1 , HW_SPEED 2 ), and are linked by the following relations: HW_WAY1=WAY1#2; HW_WAY2=WAY2#2; HW_SPEED1=SPEED1#2 AND SPEED1#1; and HW_SPEED2=SPEED2#2 AND SPEED2#1; wherein: WAY 1 # 2 is a discrete value activated by a second calculation chain for delivering a direction of movement instruction in a first direction; WAY 2 # 2 is a discrete value activated by a second calculation chain for delivering a direction of movement instruction in a second direction; SPEED 1 # 2 is a discrete value activated by a second calculation chain for delivering a speed of movement instruction in a first direction; SPEED 1 # 1 is a discrete value activated by a first calculation chain for delivering a speed of movement instruction in a first direction; SPEED 2 # 2 is a discrete value activated by a second calculation chain for delivering a speed of movement instruction in a second direction; and SPEED 2 # 1 is a discrete value activated by a first calculation chain for delivering a speed of movement instruction in a second direction.