Digitizing of Movements
Motion Capture ("mocap") is the technique of digitizing the movement of people, animals or objects. In the case of the ART Motion Capture system, markers are attached to the subject’s limbs and can be worn over normal clothes (no need for lycra body suits!). The data is captured by performing a range of movements in front of an array of pre-installed cameras.
The ART Motion Capture system has been specifically designed for applications such as immersive Virtual Reality and ergonomics analysis. It is a result of ARTs research effort in close cooperation with Volkswagen AG as part of the AVILUS research project. The system supports collaborative working, allowing the Motion Capture of up to three subjects (only upper body for the third) simultaneously.
ART's Motion Capture Convinces
- move free - when wearing the targets
- very robust - with tough, coated markers
- adaptable - to all human body sizes
- optical and hybrid solution available
- ideal for e.g. ergonomic analysis
- interfaces to: Alaska Dynamicus, Anybody, Catia, Delmia, ema, Siemens Jack, Virtools ⇒Please note that every Motion Capture software supporting BVH or C3C data can use ART tracking data!
- add tracking of fingers - with the ART Fingertracking system
Before Motion Capture can take place, it is critical that the body markers are precisely calibrated in order to produce an exact replica of the movements made by the subject. To do this, ART Motion Capture uses a single step calibration process which is fast, accurate and convenient. The subject simply makes a series of arbitrary movements which automatically calculates the bone length and the position of the targets. The results are transferred automatically to a digital manikin where they can be used directly in real time, without the need for post processing.
Optical Target Set
The ART Motion Capture set allows the precise recording of body movements. This is achieved by using 17 individual 6DOF targets which are attached to various parts of the body. This is very flexible in use because only the targets needed for the specific Motion Capture task need to be worn. For example, in a seating buck setup we use a subset of targets to track only the upper body, head and arms. The system is capable of tracking two people with full body tracking simultaneously, while a third subject’s upper body can also be tracked at the same time. The individual reflective markers have a tough plastic coating which makes them extremely resistant to the scratches and other minor damage that can be caused by rough working environments.
Our ART-Human virtual manikin software provides a fast and easy way to accurately calibrate the human model to the dimensions of the tracked subject.
Motion Capture in VR
Head mounted display (HMD)
A tracked HMD provides an excellent immersive viewing experience. And when the subjects are also wearing a Motion Capture system, they can collaborate and interact realistically with other users within a 3D environment. It has been well established that this provides major benefits for multi-person training for tasks that are either very expensive or potentially dangerous in the real world.
When planning an assembly task, it is important to know if the part itself will fit into the designed space, and also that the worker has enough space to carry out the work safely and efficiently. Motion Capture has been proven to be much more cost effective than using a physical prototype.
When designing automobile interiors, a “virtual seating buck” is used as an alternative to physical prototypes. This means that the subject uses a HMD to view a detailed 3D model of the vehicle’s interior. Often, a target set for the upper body is used, as only the position of the upper body and arms needs to be measured. Customers also use the ART Fingertracking system in conjunction with Motion Capture to give an accurate representation of finger movement.
Training staff in the use of equipment or procedures that are potentially dangerous, expensive and possibly unavailable is a constant problem (e.g. a fire in a critical area of the company or maintenance of heavy machines). Using VR based training means that staff can be trained in a safe but realistic computer generated environment where repetition of complex tasks can provide a high level of learning and understanding.
Motion Capture for Ergonomic Studies
In the production planning phase it is important to know how to assemble the product as quickly as possible, and that the worker can carry out the task safely over a long period of time. To do this, ergonomic studies are performed before the actual work place is set up. Rather than a simulation involving a virtual manikin operated by the mouse and keyboard, it is more realistic to have a worker perform the assembly task in the real world using Motion Capture. This accurately digitizes the movement involved in carrying out the work and transfers it to a virtual manikin, which in turn allows detailed analysis so that an objective comparison can be made between different tasks.
One potential drawback of carrying out operations in a real world setting is that optical tracking can sometimes be hindered by objects between the cameras and the Motion Capture targets. To deal with this, ART has developed a new hybrid Motion Capture system which uses traditional optical targets combined with robust inertial sensors. This ensures that the flow of accurate tracking data remains uninterrupted even if the subject is out of view of the cameras.
The ART Motion Capture system has a direct link to the Alaska/Dynamicus ergonomic software from IfM Chemnitz. This will calculate the ergonomic stress of the person to the EAWS (Ergonomic Assessment Work Sheet) standard.