Exercise machine safety enhancements

1. An exercise machine, comprising:

a tension generating device;

a cable coupled to the tension generating device;

a sensor monitoring the tension generating device, wherein the tension generating device includes a motor being a pancake motor;

a housing including a front side and a back side, wherein the front side and the back side are parallel to each other, and wherein the housing includes the tension generating device; and

a safety controller coupled to the tension generating device and the sensor, wherein the safety controller is configured to:

collect a sensor data from the sensor, wherein the sensor monitors cable tension, motor torque, rotation of the motor, voltage associated with the exercise machine, electrical current associated with the exercise machine, temperature associated with the exercise machine, motor speed, motor voltage, and resistance of the motor;

analyze the sensor data to determine whether the sensor data is within a specification, wherein analyzing the sensor data comprises performing one or more of the following:

A) compare the motor torque with the specification, wherein the specification is based at least in part on a physics model, wherein the physics model calculates a safe amount of torque based at least in part on the cable tension; and

in an event that the motor torque is more than the specification, determine that the sensor data is not within the specification;

B) compare the voltage associated with the exercise machine with the specification, wherein the specification is between 48 and 60 volts; and

in an event that the voltage is not within the specification, determine that the sensor data is not within the specification;

C) compare the electrical current associated with the exercise machine with the specification, wherein the specification is associated with a rating of the motor; and

in an event that the electrical current is not within the specification, determine that the sensor data is not within the specification;

D) compare the temperature associated with the exercise machine with the specification, wherein the specification is a temperature safe range; and

in an event that the temperature is not within the specification, determine that the sensor data is not within the specification;

E) compare a relationship of the motor speed with the motor voltage, wherein the specification is a speed constant of the motor; and

in an event that the relationship is not related to the specification, determine that the sensor data is not within the specification; and

F) compare a change in the resistance of the motor with the specification, wherein the specification is zero; and

in an event that the change of the resistance is not zero, determine that the sensor data is not within the specification; and

in an event the sensor data is not within the specification, entering an error stop mode for the tension generating device.

2. The exercise machine of claim 1 , wherein the sensor monitors acceleration of a frame of the exercise machine.

3. The exercise machine of claim 1 , wherein the specification is based at least in part on little or no acceleration of a frame of the exercise machine.

4. The exercise machine of claim 1 , wherein the error stop mode disables all power to the exercise machine.

5. The exercise machine of claim 1 , wherein the error stop mode disables all power to any device driving the cable.

6. The exercise machine of claim 1 , wherein the error stop mode disables a main system power supply and/or relies on an auxiliary supply to keep the safety controller operational.

7. The exercise machine of claim 1 , wherein the error stop mode reduces the cable tension.

8. The exercise machine of claim 1 , wherein the error stop mode reduces cable retraction speed.

9. The exercise machine of claim 1 , wherein the tension generating device is configured to provide an arm cable assist feature.

10. The exercise machine of claim 9 , wherein the arm cable assist feature comprises using the cable to support weight of an arm when a translatable arm mount is unlocked.