Summary of the invention
The purpose of the present invention is to propose to the foot wrist type step count set with distance measurement function, detected row by three axis accelerometer respectivelyVertical and forward acceleration at ankle when walking, the normal acceleration that when utilizing walking, sole colliding surface produces carries out meter step,Utilize the forward acceleration at ankle to carry out range measurement, can accurately obtain travel time and the travel distance of each step, thusBasic data accurately is provided for accurately calculating calorie consumption amount and burn fat amount.
The foot wrist type step count set with distance measurement function that the present invention proposes, accelerates including shell, circuit board, three axle micromechanicsDegree meter, basket tooth module and Bluetooth antenna；Described shell is worn at ankle by wrist strap, and described circuit board is fixed on shellOn, described three axle micro-mechanical accelerometers, basket tooth module and Bluetooth antenna is fixing on circuit boards；Three axle micromechanics accelerateThe signal output part of degree meter is connected with the signal input part of basket tooth module, the RF signal output of basket tooth module and bluetooth skyThe signal input part of line is connected；
Shell, the vibration produced for intermittence colliding surface at the bottom of input pin and the propulsion of ankle, shell is solid by wrist strapIt is scheduled at ankle；
Three axle micro-mechanical accelerometers, for acceleration physics sole intermittence colliding surface and ankle propulsion producedSignal is transformed into the signal of telecommunication, and the Z axis sensitive direction of three axle micro-mechanical accelerometers is perpendicular to sole, X and Y-axis sensitivity sideTo being parallel to sole；Acceleration measurement Az of Z-direction is exactly the output of the normal acceleration at ankle, X and Y-axisIt is exactly the forward acceleration at ankle that signal is respectively the resultant acceleration of Ax and Ay, Ax and Ay；
Basket tooth module, built-in single-chip microcomputer first peak to acceleration measurement Az (i.e. normal acceleration) of Z-directionValue detects and counts, and obtains the step number of walking；Then X-axis and output signal Ax of Y-axis and Ay are synthesized,Obtain propulsion acceleration, propulsion acceleration is carried out quadratic integral again, distance during walking can be obtained in real time；?After meter step data and range data be modulated into radiofrequency signal export to Bluetooth antenna；
Circuit board, is used for fixing and connecting three axle micro-mechanical accelerometers, basket tooth module and Bluetooth antenna, and hanging down shellStraight vibration and propulsion pass to three axle micro-mechanical accelerometers.
The foot wrist type step count set with distance measurement function that the present invention proposes, its advantage is, utilizes three axle micro-mechanical accelerometersDetect the vertical and forward acceleration at ankle when walking, the normal acceleration of sole colliding surface generation when utilizing walking respectivelyCarry out meter step, utilize the forward acceleration at ankle to carry out range measurement.Compared with existing step count set, the present invention proposesFoot wrist type step count set distance of each step when can accurately measure walking, for accurately calculating calorie consumption amount and burning fatFat amount provides basic data accurately；Additionally, due to three axle micro-mechanical accelerometers are close to sole (vibration source), it is to avoidThe buffering that sole is vibrated by the organs such as knee joint, hip joint and vertebra, that therefore measures is highly sensitive, increases substantiallyThe signal to noise ratio of acceleration sensor outputs signals, insensitive to the interference of the extraneous vibration such as elevator, the vehicles.
Detailed description of the invention
The foot wrist type step count set with distance measurement function that the present invention proposes, shown in its structural representation Fig. 1, including: shell1, circuit board 5, three axle micro-mechanical accelerometer 2, the basket tooth module 3 of built-in single-chip microcomputer, Bluetooth antenna 4；Shell 1 leads toCross wrist strap to be fixed on ankle；Circuit board 4 is fixed by screws on shell.Three axle micro-mechanical accelerometers 2, built-in listThe electronic devices and components such as the basket tooth module 3 of sheet machine and Bluetooth antenna 4 are fixing on the circuit board 4；Three axle micro-mechanical accelerometersSignal output part is connected with the single-chip microcomputer signal input part in basket tooth module 3, the signal output part of basket tooth module 3 and bluetoothThe signal input part of antenna 4 is connected, as shown in Figure 2.
The function of each device of this device is:
Shell 1, for the vertical vibration produced during colliding surface at the bottom of input pin and the propulsion of ankle.
Three axle micro-mechanical accelerometers 2, are transformed into telecommunications for the vertical and forward acceleration physical signalling produced by shell 1Number；
Basket tooth module 3, built-in single-chip microcomputer is first according to Z axis output signal Az of three axle micro-mechanical accelerometers 2, it is judged thatThe peak value of the normal acceleration signal of telecommunication also counts；Then X and output signal Ax of Y-axis and Ay are synthesized forward directionAcceleration, and forward acceleration is carried out quadratic integral, obtain stride data in real time；Finally will meter step data and stride dataThe radiofrequency signal being modulated into 2.4GHz exports to Bluetooth antenna 4；
Bluetooth antenna 4, for the 2.4GHz radiofrequency signal that basket tooth module 3 exports is wirelessly transmitted to smart mobile phone,By step number and the step pitch of the display walking of smart mobile phone APP application software, and according to meter step data, range data and cadence,The calorie consumption amount calculated and show in walking process and burn fat amount；
Circuit board 5, is used for fixing and connecting three axle micro-mechanical accelerometers 2, basket tooth module 3 and Bluetooth antenna 4, and willThe vertical vibration of shell 1 and propulsion pass to three axle micro-mechanical accelerometers 2.
In one embodiment of the foot wrist type step count set of the present invention, use the LIS3DH 3 axis MEMS that ST company producesMicro-mechanical accelerometer；Use TI company produce CC2541 basket tooth module, this module be built-in with enhancement mode 8051MCU,256KB flash memory able to programme and 8KB RAM；Use the 2450AT45A100 ceramic paster antenna of Johanson company.
The foot wrist type step count set with distance measurement function of the present invention, three axle micro-mechanical accelerometers therein, basket tooth module andThe electronic devices and components such as Bluetooth antenna are fixing on circuit boards, and circuit board is fixing in the enclosure, and whole step count set wrist strap is wornAt the ankle of user.
The operation principle of the foot wrist type step count set that the present invention has distance measurement function is:
People can constantly foot-up stop in the process of walking, and when stopping over, sole and ground can occur intermittent shock, clashes into and producesThe three axle micro-mechanical accelerometers 2 that are transmitted in step count set by ankle of vibration on, three axle micro-mechanical accelerometers 2Z axis sensitive direction is perpendicular to sole, the normal acceleration physical signalling that vibration produces can be transformed into the signal of telecommunication, basket tooth mouldSingle-chip microcomputer in block 3 carries out threshold decision to the normal acceleration signal of telecommunication, just can count.As it is shown on figure 3, X, Y,Z axis is respectively three sensitive directions of three axis accelerometer, and respectively X, Y, Z tri-is axial adds for Ax, Ay, AzVelocity measurement.During design, making Z axis be perpendicular to sole, Az is exactly normal acceleration；During walking, ankle only has forward direction to transportDynamic, there is no lateral movement, therefore the resultant acceleration of Ax and Ay is exactly forward acceleration.
During walking, the propulsion of ankle can produce propulsion acceleration, as shown in Figure 4, three axle micro-mechanical accelerometers 2Although X and Y-axis sensitive direction do not fix, but due to walking time ankle only have propulsion, it is impossible to have lateral movement,Therefore the resultant acceleration measuring acceleration output valve Ax and Ay of X and Y direction is exactly forward acceleration.
In walking process, when each sole all lands, foot and ground do not have relative motion, i.e. the propulsion speed of foot isZero.Utilizing in walking process, when foot lands, forward speed is zero this characteristic, calculates the travel distance (step pitch) of each stepTime, initial velocity is reset, the score accumulation error in distance measurement process can be eliminated.
Meter step data and stride data are finally modulated into the radiofrequency signal of 2.4GHz and export to Bluetooth antenna 4 by basket tooth module 3,Radiofrequency signal is wirelessly transmitted to smart mobile phone by Bluetooth antenna 4, the display walking of smart mobile phone APP application softwareStep number and step pitch, and according to meter step data, stride data and cadence, the calorie consumption amount calculating and showing in walking processWith burn fat amount.
The foot wrist type step count set with distance measurement function that the present invention proposes, foot when utilizing three axis accelerometer to detect walking respectivelyVertical and forward acceleration at wrist, the normal acceleration that when utilizing walking, sole colliding surface produces carries out meter step, utilizes footForward acceleration at wrist carries out range measurement.Compared with existing step count set, the foot wrist type step count set that the present invention proposesEach step pitch when can accurately measure walking from, for accurately calculating calorie consumption amount and burn fat amount provides base accuratelyPlinth data；Additionally, due to three axis accelerometer is close to sole (vibration source), it is to avoid the buffering that sole is vibrated by human body,Therefore the sensitivity measured is higher, and the signal to noise ratio of acceleration output signal is greatly improved, to elevator, the vehicles etc. outsideBoundary's vibration interference is insensitive.