Human sensory motor control system is extremely robust, although the sensing is distributed, sparse, quantized, noisy, and delayed. The computing in the central nervous system is slow, the muscle actuation fatigues and saturates. To study this causal factors and its consequence on the system performance of sensory motor control, it is important to develop an easy-to-use experimental platform which manipulate these factors and record the performance.
Here we presents a gaming platform called the WheelCon, which is a free and open source platform to design video games for our virtual environment that simulates riding a mountain bike down a steep, twisted, bumpy trail. WheelCon integrates with a steering wheel as it can manipulate the variables in the human sensory motor control system, such as signaling delay, quantization, noise, and the disturbance while recording the motor control trajectory and aerodynamics. It also allows research to study the layer the architects in sensory motor control, including the higher layer's goals, plans, decisions, and the lower layer's sensing, reflex and action.
On the computer running Windows 10, go to the WheelCon webpage, click Clone or download, then click Download ZIP in the popup dialog. Extract all the files to the local hard drive. Go to the manufacturer's website and download the corresponding driver for your racing wheel model.
Mount the racing wheel securely at sitting level in front of a monitor. Connect the wheel's USB cable to the PC and the power adapter to an outlet. To test the program, double-click wheelcon.
exe in the Excutable Output file's folder. Configure the settings according to monitor setup and click Play. Seat the subject down comfortably behind the wheels.
Make sure the subject is allowed adequate range of motion when handling the wheel. Click Fitt's Law Task. Click on the text box and type a name for the output file, include subject and task information.
Click Select File, then select Fitt's Law. txt as input. Click Begin Game.
Instruct the subject to track the gray zone with the green line by turning the steering wheel. This game serves to familiarize the subject with the setup. Click Mountain Bike Task.
Type the output file name and select Vision_Delay.txt. Click Begin Game to start testing. In this game, the length of the look-ahead window changes to provide advanced warning, no warning or a visual delay.
Click Mountain Bike Task, type the output file name and select Action_Delay.txt. Click Begin Game to start testing. In this game, a delay is added between the subject's wheel turning and the green line's movement.
The delay starts at zero seconds and increases by 0.15 seconds until it reaches 0.75 seconds. Click Mountain Bike Task, type the output file name and select Vision Quantization.txt. Click Begin Game to start testing.
In this game, the visual data rate is manipulated. When visual data is low, the trail can only appear in a few loose gray locations. As the visual data rate increases, the gray zone can appear in more potential locations and its movement becomes more continuous.
Click Mountain Bike Task, type the output file name and select Action Quantization.txt. Click Begin Game to start testing. In this game, action data rate is manipulated.
When data rate is at its slowest, the gray line can only go at one speed. As data rate increases, controlling wheel speed becomes finer. Click Mountain Bike Task, type the output file name and select Bump Trail.txt.
Click Begin Game to start testing. In this game, disturbances are added either as a torque on the wheel, simulating a bump, a sudden turn on the trail or the two types of disturbances combined. To retrieve test results go to the Executable Output file's folder, and look for the file with previously specified file names.
From left to right, each row in the output file specifies time, trial position, bump size, action data rate, action delay, visual delay, visual data rate, tracking error, and steering wheel angle. To develop a new input file, open the WheelCon Mntn Bike Trail Design Code. m in the Source Code folder with Matlab.
Selecting this section of the code for the desired game parameters, press Control plus T to uncomment, then press Run. The input file will be regenerated in the same folder. As the figure suggests, in games with either visual or action delays, the subject's error increased with bigger delays.
Limiting data rates in either visual input or action output resulted in larger errors. This figure shows the aerodynamics during trials with either only bumps, only turns or the two combined. As you're watching this video, you should be familiar with how to apply WheelCon to a human sensory motor control study.
