Powered prosthesis with torque dense, low ratio actuation
Disclosed herein are embodiments of a powered prosthesis. In one embodiment, the powered prosthesis may include a first joint actuator; a second joint actuator; a connector to connect the first joint actuator with the second joint actuator; and a power source connected with both the first and second joint actuator; wherein the first joint actuator and the second joint actuator are both at least backdrivable and configured such that when one of the first or second joint actuator is drawing power from the power source, the other of the first or second joint actuator may be generating power for the power source. In some embodiments, the first motor is at least a high output torque motor. In other embodiments, the second motor is at least a high output torque motor.
1. A powered prosthesis, comprising:
a first joint actuator having a first high output torque motor having a peak output torque measured over a 10 second time period of at least about 1.0 Nm;
a second joint actuator having a second motor;
a connector to connect the first joint actuator with the second joint actuator; and
a power source connected with both the first and second motors;
wherein the first joint actuator and the second joint actuator are both backdrivable, each having a static backdrive torque of less than 10 Nm, and configured such that when one of the first or second joint actuator is drawing power from the power source, the other of the first or second joint actuator can generate power for the power source.
2. The powered prosthesis according to claim 1 , further including an adapter for connecting the prosthesis with a human body and an inertial measurement unit (IMU) positioned adjacent the first joint actuator.
3. The powered prosthesis according to claim 1 , further including a controller, the controller including at least a microprocessor.
4. The powered prosthesis according to claim 1 , wherein the first joint actuator further includes a first housing having the first high output torque motor and a first transmission positioned co-axially therein.
5. The powered prosthesis according to claim 4 , wherein the first high output torque motor is a first very high output torque motor having a peak output torque measured over a 10 second time period of at least about 1.5 Nm.
6. The powered prosthesis according to claim 4 , wherein the first transmission includes a plurality of planetary gears.
7. The powered prosthesis according to claim 1 , wherein the second joint actuator includes a second housing having the second motor and a second transmission positioned co-axially therein.
8. The powered prosthesis according to claim 7 , wherein the second motor is a second very high output torque motor having a peak output torque measured over a 10 second time period of at least about 1.5 Nm.
9. The powered prosthesis according to claim 7 , wherein the second joint actuator further includes a link system connecting the second joint actuator with a joint plate, and a 6-axis load cell coupled with the joint plate.
10. The powered prosthesis according to claim 7 , wherein the second transmission includes a plurality of planetary gears.
11. The powered prosthesis according to claim 1 , wherein at least one of the first and second joint actuators is very backdrivable, and thereby has a static backdrive torque less than 5 Nm.
12. The powered prosthesis according to claim 1 , wherein at least one of the first and second joint actuators is excessively backdrivable, and thereby has a static backdrive torque less than 2.0 Nm.
13. A powered prosthesis, comprising:
a first joint actuator, the first joint actuator including a first motor and a first transmission axially aligned with the first motor, wherein the first motor is a first high output torque motor having a peak output torque measured over a 10 second time period of at least about 1.0 Nm;
a second joint actuator, the second joint actuator including a second motor and a second transmission axially aligned with the second motor, wherein the second motor is a second high output torque motor having a peak output torque measured over a 10 second time period of at least about 1.0 Nm, wherein at least one of the first and second joint actuators is backdrivable, and thereby has a static backdrive torque less than about 10 Nm;
a connector to connect the first joint actuator with the second joint actuator; and
a power source connected with both the first and second joint actuator.
14. The powered prosthesis according to claim 13 , further including an adapter for connecting the prosthesis with a human body, an inertial measurement unit (IMU) positioned above the first joint actuator, and a controller, the controller including at least a microprocessor.
15. The powered prosthesis according to claim 13 , wherein the first joint actuator is a quasi-direct drive actuator having a transmission gear ratio of less than or equal to 24 to 1.
16. The powered prosthesis according to claim 13 , wherein the first and second high output torque motors are first and second very high output torque motors having a peak output torque measured over a 10 second time period of at least 1.5 Nm.
17. The powered prosthesis according to claim 13 , wherein the first and second high output torque motors are first and second very high output torque motors having a peak output torque measured over a 10 second time period of at least 2.0 Nm.
18. The powered prosthesis according to claim 13 , wherein the second joint actuator is a quasi-direct drive actuator having a transmission gear ratio of less than or equal to 24 to 1.
19. The powered prosthesis according to claim 13 , wherein at least one of the first transmission and the second transmission has a transmission gear ratio of less than or equal to 22 to 1.
20. The powered prosthesis according to claim 13 , wherein both of the first and second joint actuators is backdrivable, and thereby has a static torque less than 10 Nm.