Hi,
I have a bldc motor and a torque sensor. I want to achieve a constant 
torque by controlling the motor current. The torque sensor communicates 
over rs485 and I would like to achieve a speed of 1000 measurements per 
second. The motor current can be set over can-bus.

At the moment everything is done by a python script running on a windows 
computer but the serial communication is too slow.

Do you have any idea which hardware I could use to solve this problem? 
Ideally the whole process of reading the sensor and adjusting the 
current would run on a separat controller.

I am thankful for your advice.

Take a look at the CY8CKIT-037 (PSOC-4 development board)

Pretty expensive but might give you some ideas