Ai-ping Yang

Study on Upper Limb Reachable Threshold in Driving Posture

This study researched on the correlations between the upper limb reachable threshold and the anthropometry data, and the gender differences were also analyzed at the same time. 11 subjects with 5 females and 6 males took part in the experiment, and their upper limb reachable thresholds in driving posture were adopted by the Vicon MX system. The anthropometry data including arm length and height were all analyzed with the reachable threshold. The correlation of height was better than arm length, and they were all strongly associated with the reachable threshold. The correlation of females was strongly associated, but the associations of males were weak. The results provided references for the research of upper limb reachable threshold.

Appropriate Operating Force of Knob in Certain Conditions

In the process of driving a car, people often use rotary knob to adjust the temperature of air-conditioning or music volume, etc. This operation is very frequent and necessary. As we all know, when we make changes on the knob, the height, angle, size and operating force of the knob will affect the comfort of the operation knob. Therefore, in order to improve use experience, it is necessary to study the comfortable operating force of knobs. This paper uses MARK-10 force measuring equipment (torque meter, measuring rotating moment), sets the test bench and sets up different knob heights (500 mm, 700 mm, 900 mm), angles (20°, 30°, 40°), sizes (16 mm, 27 mm, 36 mm), operating forces (1N, 3N, 7N) and other parameters range. Then invite 10 subjects to participate in the experiment, recording the subjective evaluation on the different operating force, finding that the subjective score of the 1N and 3N is higher. Based on this research result the appropriate knob operating force which is between 1N and 3N is concluded.

Study on the Control Device Layout of Truck Cockpit Based on User Experience

The space layout design of control actuators is very important for the ergonomic design of automobile cockpit. This study take truck cockpit as the research object, and designed a truck cockpit model as the test platform. Then, recruited 75 seasoned truck drivers as subjects, and evaluated the space layout of control actuators according to the subjective feelings of subjects. Finally, the most comfortable angles and position of control units were obtained. Based on the experimental results, the recommended range of cockpit control device layout is given. The results of this study can provide a reference for the design of truck cockpit.

Reachable Domain of Adults’ Right Leg in Sitting Posture

The reachable domain of the bending and stretching of male and female adults’ right leg in standard sitting posture was investigated. Twenty-seven healthy subjects with no movement impairing disorders were recruited. Using the VICON motion capture system, movement of the marker points pasted on the subject’s right knee, heel, and toe were recorded in four postures: (1) standard sitting position, (2) sitting with the right leg raised, (3) tiptoe position with the right leg extended backwards, and (4) heel position with the right leg extended forwards. The recorded data of all the subjects’ leg positions were statistically analyzed according to gender. The overall mean distance between the toe and heel was approximately 740 mm (male ~750 mm and female ~730 mm) when the right leg was stretched forwards and back-wards. When the right leg was raised up, the overall mean knee height was roughly 750 mm with the male average of about 800 mm and female average of about 750 mm. The overall mean knee height difference was approximately 356 mm (height difference for male was about 385 mm and height difference for female was around 306 mm) between the raised and standard sitting position. The results of this study can be used to improve the comfort of lower limb operations and operation space.

Experimental Study on Comfort Ranges of Manual Operation in Standing Position

The experimental study was conducted to assess the comfort ranges for manual operation in standing position. Twenty healthy young people (10 males and 10 females) were recruited as study subjects. With the example of an index finger push-button operation, the acceptable height ranges (approximately 800–1200 mm) of manual operation in standing position were determined by the experiment. Specifically, the five experimental heights from 800 mm to 1200 mm were set up with the step interval being 100 mm. In the operating plane (workstation), the 50 mm vertical and horizontal spacing buttons were arranged, respectively. The acceptable operating regions of the test height table can be obtained through statistical analysis of the forefinger push-button operations of all study subjects. Thus, the corresponding comfort ranges of manual operation on other experimental height planes can be replicated. The study results yielded certain practical values of mounting position for manual devices in the ergonomic design and assessment.

Experimental Research of Range of Motion About Wrist Joint

Objective: To investigate the range of motion (ROM) of wrist joint in human body, and the difference about ROMs between man and woman in subgroups and how it relates to age itself;

Experimental Study on Discrimination Thresholds for Haptic Perception of Size in Manual Operation

Objective: This experimental study was designed to measure discrimination thresholds for haptic perception of size in manual operation. Methods: Common manual operation modes with finger pressing or pulling, three finger pinch or grip, and hand grip were used in this study. Taking the index finger pressing operation as an example, the distal phalanx finger length and the width of the index finger were measured in order to determine the size range of sample buttons. The assessment procedure along with the measurement data sheet of index finger regarding pressing operation was designed. Study subjects were recruited and discrimination thresholds for the size haptic perception of the index finger were measured and analyzed.

Experimental Research for Motion Ranges of Knee Joints

To investigate the range of motion (ROM) of knee joints in the human body, the difference of ROMs between man and woman in subgroups, and how the difference of ROMs relates to age itself; One hundred healthy volunteers of ages 18–60 were recruited to complete the study. They were divided into two groups, with half of them male. The VICON motion capture system was used to measure ROMs of knee joint. The average value of knee joint ROMs for two groups was calculated. The changes in the ROM for two groups were compared along with the differences in the ROM between male and female, and between the left and right knee joints. ROMs of knee joints decreased as the age increased. The difference between the ROMs in the two groups was not significant. Female ROMs of knee joints were bigger than the male in the same age group.

Comfort Posture and Position of Push-Pull Operation of the Sagittal Plane in Standing

Push-pull operation is often used in daily work and life. The position of the operating lever, the grab bar, handrail, and the buckle slot is one of the main factors that affect the push-pull task performance. Through the test analysis of 30 people’s push and pull task, the comfort movement ranges of the elbow joint and the shoulder joint, as well as the acceptable height ranges of hand in the sagittal plane were obtained. The research results demonstrated some practical applications for the comfort evaluation of single light load push-pull operation and the ergonomics evaluation of the general manual control layout and position.

Experimental Study on Grip Ergonomics of Manual Handling

Improper design for the grip structure will lead to inefficient operation or work injuries. The study purpose was to simulate the shape, size, and position of a gripping structure by using a 30 kg rectangular box as a heavy object, to enhance the health and comfort for an operator. Ergonomic evaluation experiments for grip structural factors were performed by samples testing and virtual simulation methods for operational tasks. Research methods and results in this study have some reference meanings and guidance for the man-machine adaptation design regarding the shape, size, and location of manual handling gripping structure of products, supplies and equipment.